1 . Randy Kraus was disabled. His left side was useless. He'd been a police officer before, and he was strong and able. Now, he felt he could do nothing.
His trouble started with Parkinson's disease, but it didn't end there. In July, 2002, the 60-year-old Kraus went into the hospital for an operation on his brain to control the shaking. But during the operation，he had a stroke. He was paralyzed. The doctor said, “You may never walk again and you might not even be able to talk.”
Kraus found that he couldn't lift a fork or take a drink by himself. Physical treatment was so painful and slow. What did he have to live for? So Kraus held the gun against his head. Feeling the cold metal on his skin, he began to consider the pain he would cause for his wife, daughters and grandchildren. He didn't pull the trigger (扳机)．
Andrew Garud, his exercise physiologist, told him, “You are where you are. The pace would be slow；the pain would be real. But as long as you are alive, you will have the ability to get better.”
After three months of working with Garud, Kraus wanted to see if he could stand.
He could. Then he took three steps, sat down and cried like a baby.
One step, as they say, led to another. Next he managed a short walk along the edge of a boxing ring (拳击台) in the health club. It was the hardest fight of Kraus's life. People at the gym cheered him on. Garud kept saying he could do more. Now, Kraus can brush his teeth，shave himself and get around the house with a walker. Only the disabled can fully understand little success.
1. According to the passage，we can learn that ________.| A．the stroke during the operation on his brain led to Kraus' disability |
| B．Kraus' operation in 2002 was performed by Andrew Garud |
| C．doing exercise can help cure Parkinson's disease |
| D．Kraus will lead a normal life as a healthy person in the future |
| A．Everyone in the world has the right to be alive. |
| B．It's necessary for people to do exercise to keep healthy. |
| C．One should try to lead a better life. |
| D．As long as a person is alive, he will have a chance to be better. |
| A．Optimism. | B．Strong mindedness. |
| C．Sympathy. | D．Generosity. |
2 . Several weeks ago, a mysterious Christmas card dropped through our mailbox. The envelope was addressed to a man named Raoul, who, I was relatively certain, did not live with us. The envelope wasn’t sealed, so I opened it. The inside of the card was blank. Ed, my husband, explained that the card was both from and to the newspaper deliveryman. His name was apparently Raoul, and Raoul wanted a holiday tip. We were meant to put a check inside the card and then drop the envelope in the mail. When your services are finished at 4 a.m., you can’t simply hang around, like a hotel bellboy expecting a tip. You have to be direct.
So I wrote a nice holiday greeting to this man who, in my imagination, fires The New York Times from his bike aimed at our front door, causing more noise with mere newsprint than most people manage with sophisticated(复杂的) black market fireworks. With a start, I realized that perhaps the reason for the 4 a.m. wake-up noise was not ordinary rudeness but carefully executed spite(怨恨): I had not tipped Raoul in Christmas past. I honestly hadn’t realized I was supposed to. This was the first time he’d used the card tactic(策略). So I got out my checkbook. Somewhere along the line, holiday tipping went from an optional thank-you for a year of services to a Mafia-style protection racket (收保护费组织).
Several days later, I was bringing our garbage bins back when I noticed an envelope taped to one of the lids. The outside of the envelope said MICKEY. It had to be another tip request, this time from our garbage collector. Unlike Raoul, Mickey hadn’t enclosed his own Christmas card from me. In a way, I appreciated the directness. “I know you don’t care how merry my Christmas is, and that’s fine,” the gesture said. “I want $30, or I’ll ‘forget’ to empty your garbage bin some hot summer day.” I put a check in the envelope and taped it back to the bin. The next morning, Ed noticed that the envelope was gone, though the trash hadn’t yet been picked up: “Someone stole Mickey’s tip!” Ed was quite certain. He made me call the bank and cancel the check. But Ed had been wrong. Two weeks later, Mickey left a letter from the bank on our steps. The letter informed Mickey that the check, which he had tried to cash, had been cancelled.
The following Tuesday morning, when Ed saw a truck outside, he ran out with his wallet. “Are you Mickey?” The man looked at him with scorn(轻蔑). “Mickey is the garbageman. I am the recycling.” Not only had Ed insulted(侮辱) this man by suggesting that he was a garbageman, but he had obviously neglected to tip him. Ed ran back inside for more funds. Then he noticed that the driver of the truck had been watching the whole incident. He peeled off another twenty and looked around, waving bills in the air. “Anyone else?”
Had we consulted the website of the Emily Post Institute, this embarrassing break of etiquette (礼节) could have been avoided. Under “trash/recycling collectors” in the institute’s Holiday Tipping Guidelines, it says: “$10 to $30 each.” You may or may not wish to know that your hairdresser, mailman and UPS guy all expect a holiday tip.
1. The newspaper deliveryman put a blank card inside the envelope because________..| A．he wanted the couple to pay for the newspaper | B．he forgot to write a few words on it |
| C．he used it to ask for a Christmas tip | D．he was afraid of asking for a tip in person |
| A．didn’t like Raoul’s way of delivering the paper |
| B．didn’t realize why Raoul delivered the paper that way before |
| C．didn’t know that Raoul delivered the paper for them |
| D．didn’t feel it necessary to meet Raoul when he came |
| A．excited | B．happy | C．embarrassed | D．forced |
| A．He wrote a letter to the couple afterwards. |
| B．He failed to collect the money from the bank. |
| C．He wanted the couple to send him a Christmas card. |
| D．He collected both the check and the garbage that day. |
| A．Ed was desperate to correct his mistake | B．Ed only wanted to give money to Raoul |
| C．Ed was unwilling to tip the truck driver | D．Ed no longer wanted to give them money |
| A．their garbage bin might not be emptied one day if the writer didn’t give tips |
| B．the writer could have avoided giving tips if they had consulted the website of the Emily Post Institute |
| C．the writer’s husband didn’t know Raoul at all |
| D．the writer’s family was too poor to give the tips |
3 . Chinese scientists applied a specially developed new technology to laser-ranging (激光测距) telescopes, which enabled them to identify space waste more effectively than previous techniques, according to a study published in the Journal of Laser Applications. “After improving the pointing accuracy of the telescope through a neural (神经的) network , space debris (碎片) with a cross sectional area of one square meter ( 10 square feet) and a distance of 1 ,500 kilometers (932 miles ) can be identified," Tianming Ma, an author of the study from the Chinese Academy of Surveying and Mapping, Beijing and Liaoning Technical University, Fuxin, said in a statement.
Debris can include non-functional spacecraft, abandoned launch vehicle stages, and other mission-related space waste. It is very dangerous for astronauts and spacecraft in orbit above the Earth as they travel very fast — up to 18,000 miles per hour. Worryingly, there are probably many millions of tiny debris pieces in low-Earth orbit, and tens of thousands larger than a softball, NASA said. Fortunately, there have been surprisingly few collisions.
Laser-ranging technology has previously been used to find space waste. However, these systems have their limitations when it comes to accurately identifying small, fast-moving pieces. In fact, previous laser-ranging methods have only been accurate to within about 0. 6miles.
In an attempt to overcome the inaccuracies in laser-ranging techniques, the Chinese team used so-called neural networks to improve the effectiveness of their telescope system. Neural networks are computing systems which are inspired by biological networks in the brain. They can learn to become better at tasks without being given a specific set of rules to follow. Ma and his team tested this method against more traditional techniques at the Beijing Fangshen laser range telescope station. According to the team, this is the first time that neural network has been used to significantly improve the pointing accuracy of a laser-ranging telescope. They say that the latest findings could have significant meaning for guiding spacecraft in orbit.
1. What are laser-ranging telescopes designed to do?| A．Set up a neural network in space. |
| B．Find out the precise position of space waste. |
| C．Help the telescopes work more accurately. |
| D．Confirm the amount and size of space waste. |
| A．Useless man-made objects in space. | B．Fast-travelling softballs. |
| C．Launch vehicle stages in low-Earth orbit. | D．Satellites moving too fast. |
| A．Rule followers. | B．Biological computing. |
| C．Machine learning. | D．Spacecraft guidance |
| A．New Technology Used to Find Space Waste |
| B．The First Telescope to Handle Space Debris |
| C．An Invention for Astronauts and Spacecraft |
| D．The Substitute for Laser-ranging Telescopes |
4 . Round and Round They Go
Space is becoming more crowded. On December 3, a Falcon 9 rocket made by Space X thundered into the sky. On board were 64 small satellites, more than any American company had launched before in one go. They have a variety of uses, from space-based- radar to the monitoring of radio-frequency- emissions.
These objects are part of the latest breed of low-Earth-orbit (LEO) satellites. This launch is just taste of what is planned. Space X and One Web, a communications firm, plan to launch satellites in their thousands, not hundreds. The pair are set to double the total number of satellites in orbit by 2027.
That promises to change things dramatically on Earth. LEO satellites can bring internet connectivity to places where it is still unavailable or unaffordable. This will also be a lasting source of new demand for the space economy. Morgan Stanley, a bank, projects that the space industry will grow from $350 billion in 2016 to more than $1. I trillion by 2040. New internet satellites will account for a half this increase.
For that to happen, however, three worries must be overcome. Debris(碎片)is the most familiar concern. As long ago as 1978, Donald Kessler, a scientist at NASA, proposed situation in which, when enough satellites were packed into low-Earth orbits, any collision could cause a chain reaction which would eventually destroy all space craft in its orbital plane(平面). The syndrome which bears Mr. Kessler's name weighs heavily on the minds of executives at the new satellite firms. Debris could cause entire tracts(广阔的一片) of space to be unusable for decades.
Solutions exist. One is to grab malfunction satellites and pull them down into Earth's atmosphere. Another is to monitor space more intensively for debris; a US Air Force program me called Space Fence is due to start in 2019. But technology is only part of the answer. Rules are needed to govern the safe disposal(清除) of old satellites from low-Earth orbit. The United States' Federal Communications Commission is revising its regulations with this in mind. Other countries should follow suit.
Cyber-security is a second, long-standing worry. Hackers could take control of a satellite and seal intellectual property, redirect data flows or cause a collision. The satellite industry has been slow to respond to such concerns. But as more of the world's population comes to rely on the infrastructure of space for access to the internet, the need for action intensifies.
The third issue follows from the first two. If a simple mistake or a cyber-attack can cause a chain reaction which wipes out hundreds of billions of dollars of investment, who is liable? Underwriters(保险商) are studying the plans of firms that wish to operate large numbers of satellites. But there is a long way to go before the risks are well understood, let alone priced.
As space becomes more commercialized mind-bending prospects open up: packages moved across the planet in minutes by rocket rather than by plane, equipment sent to other small planets, passengers launched into orbit and beyond. All that and more may come, one day. But such activities would raise the same questions as LEO satellites do. They must be answered before the space economy can truly develop.
1. What can we learn about LEO satellites from the passage?| A．They are supposed to limit the space economy. |
| B．They are expected to increase in large numbers. |
| C．They are designed to move beyond the Earth as far as possible. |
| D．They are mainly intended to bring internet connectivity to remote areas. |
| A．depending entirely on the modern technology |
| B．monitoring the movement of spaceships carefully |
| C．strengthening rules to remove old satellites safely |
| D．destroying all the satellites with problems instantly |
| A．Measure. | B．Increase. | C．Spread. | D．Repeat. |
| A．Lack of satellite regulations. |
| B．Loss of intellectual property. |
| C．Crisis of confidence in the field. |
| D．Slow response of satellite industry. |
| A．It should be further confirmed for its ownership. |
| B．It should be continued because of its advantages. |
| C．It should be done carefully to avoid potential risks. |
| D．It should be stopped in face of the space economy. |
5 . In 1997, a group of twenty British women made history. Working in five teams with four women in each team, they walked to the North Pole. Apart from one experienced female guide, the other women were all ordinary people who had never done anything like this in their lives before. They managed to survive in an environment which had defeated several very experienced men during the same period.
Once on the ice, each woman had to ski along while dragging a sledge (雪橇) weighing over 50 kilos. This would not have been too bad on a smooth surface, but for long stretches (一片地域), the Arctic ice is pushed up into huge piles two or three meters high and the sledges had to be pulled up on side and carefully let down the other so that they didn’t crash. The temperature was always below freezing point and sometimes strong winds made walking while pulling so much weight almost impossible. It was also very difficult to put up their tents when they stopped each night.
In such conditions the women were making good progress if they covered fourteen or fifteen kilometers a day. But there was another problem. Part of the journey was across a frozen sea with moving water underneath the ice and at some points the team would drift (漂流) back more than five kilometers during the night. That meant that after walking in these very terrible conditions for ten hours on one day, they had to spend part of the next day covering the same ground again. Furthermore, each day it would take three hours from waking up to setting off and another three hours every evening to set up the camp and prepare the evening meal.
So, how did they manage to succeed? They realized that they were part of a team. If any one of them didn’t pull her sledge or get her job done, she would endanger the success of the whole expedition (远征探险). Any form of selfishness could result in the efforts of everyone else being completely wasted, so personal feelings had to be put to one side. At the end of their journey, the women agreed that it was mental effort far more than physical fitness that got them to the North Pole.
1. What was so extraordinary about the expedition?| A．It was a new experience for most of the women. |
| B．The women did not have any men with them. |
| C．The women had not met one another before. |
| D．There was no one leading it. |
| A．being left behind | B．damaging the sledges |
| C．falling over on the ice | D．breaking the ice |
| A．they got too tired | B．they kept getting lost |
| C．the ice was moving backwards | D．the temperatures were very low |
| A．Strict but caring. | B．Proud but patient. |
| C．Honest and devoted. | D．Determined and strong-willed. |
| A．Experience must be bought. |
| B．Facts speak louder than words. |
| C．He who risks nothing gains nothing. |
| D．Motivation and teamwork achieve goals. |
6 . There’re currently 21.5 million students in America, and many will be funding their college on borrowed money. Given that there’s now over $1.3 trillion in student loans on the books, it's pretty clear that many students are far from sensible. The average student’s debt upon graduation now approaches $40, 000, and as college becomes ever more expensive, calls to make it “free” are multiplying. Even Hillary Clinton says that when it comes to college, “Costs won’t be a barrier.”
But the only way college could be free is if the faculty and staff donated their time, the buildings required no maintenance, and campuses required no utilities. As long as it's impossible to produce something from nothing, costs are absolutely a barrier.
The actual question we debate is who should pay for people to go to college. If taxpayers are to bear the cost of forgiving student loans, shouldn’t they have a say in how their money is used?
At least taxpayers should be able to decide what students will study on the public dime. If we're going to force taxpayers to foot the bill for college degrees, students should only study those subjects that are of greatest benefit to taxpayers. After all, students making their own choices in this respect is what caused the problem in the first place. We simply don’t need more poetry, gender studies, or sociology majors. How do we know which subjects benefit society? Easy.
Average starting salaries give a clear indication of what type of training society needs its new workers to have. Certainly, there’re benefits to a college major beyond the job a student can perform. But if we’re talking about the benefits to society, the only thing that matters is what the major enables the student to produce for society. And the value of what the student can produce is reflected in the wage employers are willing to pay the student to produce it.
A low wage for elementary school teachers, however, doesn’t mean elementary education isn’t important. It simply means there’re too many elementary school teachers already.
Meanwhile, there’re few who’re willing and able to perform jobs requiring a petroleum engineering major, so the value of one more of those people is very high.
So we can have taxpayers pick up students’ tuition in exchange for dictating what those students will study. Or we can allow students both to choose their majors and pay for their education themselves. But in the end, one of two things is true:
Either a college major is worth its cost or it isn’t. If yes, taxpayer financing isn’t needed. If not, taxpayer financing isn’t desirable. Either way, taxpayers have no business paying for students’ college education.
1. What does the author think of college students funding their education through loans?| A．They only expect to get huge returns. |
| B．They are acting in an unwise way. |
| C．They benefit at taxpayers’ expense. |
| D．They will regret doing so someday. |
| A．Work even harder to repay society. |
| B．Choose their subjects more carefully. |
| C．Choose majors that will serve society’s practical need. |
| D．Allow taxpayers to participate in college administration. |
| A．It is well reflected in their average starting salary. |
| B．It is to be proved by what they can do on the job. |
| C．It is underestimated by profit-seeking employers. |
| D．It is reflected in how they remove social barriers. |
| A．Students should think carefully whether to go to college |
| B．Taxpayers should only finance the most gifted students. |
| C．The worth of a college education is open to debate. |
| D．College students should fund their own education. |
7 . At 12, my father decided to take me on a trip to France. I had never been out of the country before, so I was very excited. My aunt, my father and I went around with my father showing us all the unbelievable sites in Paris. None of us spoke much French but we loved the city.
We had taken the subway all over the city and were congratulating ourselves on our mastering what is honestly an excellent subway design that is pretty easy to follow. We decided visit Versailles by train. We chatted happily along the way until my father realized we were into the French countryside and no one around spoke English.
We reached the end of the line and felt afraid when everyone finally left the train. An old man and his grandchild noticed us and came to help. He spoke no English, so in broken French we tried to explain. When he finally understood, this great man settled his grandson and showed us to the correct train and then boarded with us.
Later we knew the truth that there was a train transfer (转乘) and he didn't want us to miss it.
This kind man rode a train for an hour and a half out of his way to make sure that three Americans got where they wanted to be. He refused to let us pay for his ticket. He did it all with a gentle smile and patted our hands gently at the stop. Then in his quiet way, he boarded the train to return the way he had come.
What impressed me most was the man and his kindness during the amazing trip. Some Americans think the French are rude for some reason, but I always try to persuade them to change their minds with this very story.
1. What happened to the author and his family on the train?| A．They missed their stop. |
| B．They lost their packages. |
| C．They couldn't find the right line. |
| D．They argued over the nest destination. |
| A．By paying for their train tickets. |
| B．By showing them the returning way. |
| C．By inviting them to travel together. |
| D．By leading them to their place. |
| A．Travelling enriches one's life. |
| B．Being kind is a good manner. |
| C．Seeing is believing. |
| D．Helping others brings great pleasure. |
8 . I’ve recently found myself wondering if I could do without Google Maps. It is, I think, the only app on my phone I’d really miss were I to swap my smartphone for a “dumb” one that handles only calls and text messages.
Why am I thinking about this? It’s because every time I try to read a book, I end up picking up my phone instead. I keep interrupting my own train of thought in order to do something that I don’t consciously want to do.
This is not accidental. Developers have become even more unashamed in their attempts to keep us hooked on our smartphones. Some of them speak in the language of addiction and behavioural psychology, though most prefer the term “persuasive tech”. In itself, persuasive tech is not a new idea — an academic named BJ Fogg has been running classes from a “persuasive tech lab” at Stanford since the late 1990s. But as smartphone ownership has rocketed and social-media sites have been born, persuasive tech has vastly expanded its reach.
One company, Dopamine Labs — named for the chemical released in the reward center of the brain — offers a service to tech businesses wanting to “keep users engaged”. Founder Ramsay Brown tells me he wants people to understand that “their thoughts and feelings are on the table as things that can be controlled and designed”. He thinks there should be more conversation around the persuasive power of the technologies being used. “We believe everyone has a right to cognitive liberty, and to build the kind of mind they want to live in,” he says.
The poster child of the resistance movement against addictive apps is former Google “design ethicist” Tristan Harris. He thinks the power to change the system lies not with app developers but with the hardware providers. In 2014, Harris founded “Time Well Spent”, a group that campaigns for more moral design practices among developers.
Any tech business that relies on advertising profits is motivated to hold its users online for as long as possible, Harris says. This means apps are specifically designed to keep us in them. Apple, on the other hand, wants to sell phones but doesn’t have a profit stream so tightly connected to the amount of time its customers spend online. Harris hopes that companies like Apple could use their influence to encourage more morally designed apps.
While I wait for Apple to sort this out, I find myself longing for something called a “Light Phone”, a credit-card-sized handset that does absolutely nothing but make and receive calls. Price tag? $150. Seems expensive. But the company’s website is very persuasive.
1. According to the author, what makes us so glued to our smartphones？| A．People's inborn behaviours. | B．App developers’ intention |
| C．User-friendly apps | D．Hardware providers |
| A．Tech businesses have gone too far in controlling users’ minds |
| B．Persuasive technologies are dangerous to users’ cognitive liberty. |
| C．The persuasive power of the technologies deserves more attention |
| D．Everyone can live the life they desire by using persuasive technologies. |
| A．The advertiser | B．The advocate |
| C．The opponent | D．The founder |
| A．Do we have a right to cognitive liberty? |
| B．What have persuasive tech done to us? |
| C．Why a dumb phone is a smart move? |
| D．How smartphones shape our minds? |
9 . Now, chemists have discovered new potential in abundant building blocks: Through a series of reactions, scientists have shown that conventional bricks can be transformed into energy storage devices powerful enough to turn on LED lights. “What we have demonstrated in our paper is sufficient enough for you to light up emergency lighting that's in a hallway or sensors that could be put inside the walls of a house, "said Julio M. D’ Arcy, an assistant professor of chemistry at Washington University in St. Louis, Missouri, and one of the study's authors. "The next step is trying to store more energy, so that you can power bigger devices--like maybe a laptop--directly from the walls of the house. ”
“Bricks have been prized by architects for their capacity to store heat, but using them to hold electricity has never been tried before, "D'Arcy said. To allow the bricks to store electricity, the researchers pumped a series of gases inside the brick. "The gases react with the brick's chemical components, coating them with a web of plastic nanofiber (纳米纤维）known as a PEDOT, which is a good conductor of electricity, "he said. Though PEDOT can store large amounts of energy, this supercapacitor (超级电容器）cannot hold onto that charge or deliver sustained energy over long periods of time like batteries can. “A battery will give you energy density that will allow you to drive 300 miles, but a supercapacitor will allow you to accelerate very quickly at a red light,” D’ Arcy said.
Still, scientists see potential in the bricks as a possible green energy solution. Right now, these "smart bricks" cannot compete with the energy storage potential of the lithium-ion (锂离子）batteries used in many solar power systems. However, there is hope that this new technology could be developed to provide a new storage method using readily available materials.
“The performance is a long way short of custom-made supercapacitors, but the principle is proven and there is significant room for improving the storage characteristics by optimizing the structure and chemistry of the bricks,” said Dan Brett, a professor of electrochemical engineering at University College London, who was not involved in the study.
1. What will the scientists do about the bricks next according to M. D'Arcy?| A．Put the bricks into commercial use. |
| B．Refer their paper to academic journals. |
| C．Expand the bricks' ability of storing power. |
| D．Develop new smart laptop with powered bricks. |
| A．It allows bricks to take up less space. |
| B．It can protect bricks with a powered coat. |
| C．It helps bricks store and conduct electricity. |
| D．It can make the powered vehicles travel farther. |
| A．They need much more development. |
| B．They are more environmentally-friendly. |
| C．They will be released into the market soon. |
| D．They can be made according to consumers' requirements. |
| A．Making the most of. | B．Trying out for. |
| C．Breaking up with. | D．Breaking away from. |
10 . 
Pesticides might just be a bee's worst enemy. They harm their brains, slow down their reproduction, and even kill their buzz. Now it seems they damage their social lives and reduce their ability to care for their young.
While previous studies have shown that commonly used neonicotinoid（新烟碱类）pesticides make bees sick and affect how they search for food and navigate, a new study gives more of an idea of how these chemicals affect the internal workings of a colony（种群）. Studying these effects has proved difficult, so the team employed a new technique. They stuck tiny QR codes to the backs of humblebees and tracked their movements using a robotic camera.
The researchers looked at 12 colonies housed in a lab, giving some the same level of imidacloprid—the world's most commonly used pesticide—that they'd be exposed to in the wild while keeping others pesticide-free as controls. They checked on them for a few minutes 12 times a day. The findings are published in the journal Science.
Unfortunately, the researchers found a number of obvious differences between the bees exposed to the pesticide and the controls. The bees given neonicotinoids spent less time interacting with other bees and more time resting. This pause in activity tended to happen more at night, but the researchers aren't sure why.
"Bees actually have a very strong circadian rhythm（生理节奏）," lead author James Crall explained in a statement. "So what we found was that, during the day, there was no statistically observable effect, but at night, we could see that they were crashing. We don't know yet whether the pesticides are destroying circadian gene regulation or if this is just some, maybe physiological feedback…But it suggests that, just from a practical perspective, if we want to understand or study these compounds, looking at effects overnight matters a lot."
1. What does the new study suggest about pesticides' effect on bees?| A．Pesticides lead to their disease. |
| B．Pesticides slow down their brain function |
| C．Pesticides upset their community. |
| D．Pesticides damage bees' internal parts. |
| A．The tools used to observe the bees. |
| B．The data recorded by the robotic camera |
| C．The researchers conducting the experiments. |
| D．The bees kept free from the pesticides. |
| A．The circadian rhythm of bees is stronger during the day. |
| B．It is vital to study the performance of bees at night |
| C．It is certain that pesticides affect bees only at night. |
| D．The pesticides do great harm to circadian gene regulation of bees. |
| A．To inform people of the worrying effects of pesticides. |
| B．To check the best time to observe experimental results. |
| C．To call for the toughest ban on the chemicals. |
| D．To recommend measures to improve the quality of pesticides. |
