DNA is the whole “map” of the human body. It’s something that all humans have, and it tells the body what to do. DNA is the reason that we look like our parents, because we get some of their DNA to make our own.
People have been trying to understand the human body for a long time. In 1860, Mr. Mendel discovered why we look similar to other people in our family. It’s because of small things called “genes（基因）” in our body. In 1953, two scientists, Watson and Grick, found out that those small parts are real messages. They are written in the DNA with a special language.
In 1961, another two scientists found the first “word” that they could understand in that language. It shows how DNA tells the cell（细胞）to build its parts. So far, scientists have found all the words in the DNA map, but we don’t understand what they all do. By understanding what just one “word” means, we can help to save people from several illnesses. So the more we understand, the more doctors will be able to do.
Most people hope that this will help to make better medicine to help sick people. Other people worry that when we learn more “words” and find out more information, we’ll use it in the wrong way, just to make people more attractive（有吸引力的）, or stop sick people getting jobs.
1. Who discovered why we look like other people in our family in 1860?| A．Grick. | B．Watson. | C．Mr. Harris. | D．Mr. Mendel. |
| A．All the words in the DNA map. |
| B．Small things called “genes” in our body. |
| C．The first “word” that they could understand in that language. |
| D．The small parts are written in the DNA with a special language. |
| A．Stop them getting jobs. | B．Make better medicine. |
| C．Tell them what to do. | D．Make them attractive. |
| A．DNA tells the cell to build its parts |
| B．DNA is the whole “map” of the human body |
| C．we look like our parents because of “genes” in our body |
| D．we have understand what all the words in the DNA map do |
| A．It can be good and bad. | B．It can be good. |
| C．It can be bad. | D．It can be good but won’t work. |
相似题推荐
【推荐1】Pass the Salt
“Pass the salt，please!” Maybe you hear that at meals. That's because people like salt. Also，people need salt. Salt isn't a food. It's a mineral（矿物质）. It doesn't grow like a plant. It is found in rocks.
Here is why we need salt. Our bodies contain much water. Salt is in the water. We lose salt when we sweat. We also lose it if we bleed. That’s why we need more salt every day. True，it may make our food taste better，but it is more important than that. People who don't get enough salt may die!
Salt is found in many places. It is in the oceans and underground. Much of our salt comes from salt mines. People work in the mines. They dig out big chunks（大块）of salt. The salt chunks are brought to the surface. There they are crushed. Some of the salt becomes small chunks. These chunks are used to make many things，such as foods and chemicals. Some crushed salt becomes tiny grains. This is the salt that ends up on your table.
Salt has long been important to people. In ancient times，people were even paid with salt! In fact，our word “salary" comes from the Roman word for salt. People long ago used salt to keep meat fresh. The meat was packed in salt. This kept it from spoiling. People also used salt as a medicine. That's why the word “salt” sometimes means “good”. “You're the salt of the Earth，” people say. That's their way of saying. “You're OK with me!”
1. Where is salt from？| A．Plants. | B．Rocks. | C．Meals. | D．Minerals. |
| A．We sweat more. | B．We bleed a lot. | C．We may die. |
| D．We make the food better. | ||
| A．paying for things | B．keeping meat fresh | C．making money | D．working as a medicine |
| A．Salt is necessary for all people. |
| B．How do people find salt. |
| C．How to break salt into small pieces. |
| D．People take salt out of the Earth. |
【推荐2】You might ask, “Where will the universe go? Will it ever come to an end?”
Scientists have been thinking about these questions. However, it’s hard to know what will happen. After all, the universe is so big. Still, scientists have made some guesses about the fate of the universe. As US poet Robert Frost once wrote, “Some say the world will end in fire, some say in ice.”
In the 1800s, the study of heat showed that the universe might someday experience “heat death”. Our universe “runs” properly because of temperature differences. It’s kind of like how a car engine is able to run because it’s hotter inside the engine than outside the engine. But if temperatures become the same everywhere in the universe, certain energy processes will stop working and the universe will die. Will the universe continue to expand? And what will happen next? Here are some related theories.
The Big Rip(大撕裂) We know that our universe is expanding. Dark energy causes it to expand faster and faster. This theory suggests that this expansion will continue forever. Finally, the expansion’s speed will become so great that everything in the universe will be ripped apart.
The Big Freeze(大冻结) As the universe expands, galaxies, stars and planets will pull away from each other. Light from stars will no longer reach the Earth. This will make the universe colder. Finally, the temperature of the universe will reach absolute zero. All movement stops at this temperature.
The Big Crunch(大崩坠) This theory is different from the other two. Instead of expanding forever, it suggests that the mass of the universe will reverse the expansion. Then, like a star that grows too large, the universe will collapse in on itself, maybe creating a new condition.
1. The US poet Robert Frost’s words mean ________.| A．it’s interesting to predict the future |
| B．it’s hard to predict the future |
| C．the future will end in fire |
| D．the future will end in ice |
| A．the Earth might become hotter and hotter |
| B．the Earth’s energy processes are different from the car’s |
| C．the universe will be sure to expand in the future |
| D．the universe “runs” properly because it has the same temperature |
| A．the Big Rip | B．the Big Freeze | C．the Big Crunch | D．the Big Bang |
| A．speed up | B．fly up | C．set down | D．fall down |
| A．The theory of the Big Crunch is offered by scientists from the us. |
| B．Humans didn’t start to study the universe until the 1800s. |
| C．Light from stars won’t get to the Earth when the universe expands. |
| D．When the universe gets hot, it will become very active. |
【推荐3】Parents of very young children know this: You catch your child in the act of stealing the cookie—the evidence of candy written on his or her face. However, you get a wide-eyed denial:" I didn't do it!"
Learning to tell the truth, even at the risk of punishment, is an important part of moral (道德) development, and new research suggests it can take seven or more years for kids to get there.
Early 2017 Professor Craig E.Smith published a study. He and his workmates chose 48 children between four and nine years of age. They told the kids a story about a boy or girl doing something wrong, such as taking a classmate's toy or candy, and then either lying about the wrongdoing to a parent or confessing (承认) it. In each case, they asked the children. How would the child feel? How would the mother feel?
The children's answers were generally divided according to age, which is in agreement with the stolen candy, lying and getting unpunished. They imagined the parent in the study would be angry with the child who confessed. However, the seven-to-nine-year-olds were more likely (可能的) to think the child would feel better confessing the crime and that the parent would have positive (积极的) feelings towards a confessor.
Smith says, "kids of all ages who expect that a parent would feel happy about a child's confession are more likely to tell the truth rather than lie. Reward the honesty even if you feel you must punish the wrong action." He adds, what parents can learn from these studies is to listen calmly without getting angry right away when their child confesses.
1. What does the underlined word "denial" in Paragraph 1 mean?| A．委屈 | B．责备 | C．否认 | D．拒绝 |
| A．kids can't tell "right" from "wrong" |
| B．it takes time for kids to learn to tell the truth |
| C．it's wrong to punish kids for telling the truth |
| D．all the kids are willing to confess to a bad act |
| A．Older kids are more likely than younger children to confess to a bad act. |
| B．Younger children are more likely than older kids to confess to a bad act. |
| C．The 4-5-year-olds would feel better confessing the crime. |
| D．The 7-9-year-olds thought parents would be angry with their confessions. |
| A．Parents should at once punish the children who lied. |
| B．Parents should tell children the wrongness of lying. |
| C．Parents should never get angry after their children's confessions. |
| D．Parents should show positive feeling about their children's confessions. |
【推荐1】Boyan Slat has been dreaming of cleaning up the world’s oceans（海洋）ever since he was a child.
In 2010, the 16-year-old boy went on a vacation in Greece. “I saw more plastic bags than fish in the water.” he said. He realized there are more and more ocean pollution these years.
In 2013, Slat decided to clean up ocean rubbish. Now the 25-year-old designed and set up the world’s first ocean cleanup system with his team.
Every year, over 8 million tons of plastics were thrown into oceans, and it needs at least 500 years to reduce the plastic pollution. In 2018, the World anomic Forum said that the weight of ocean plastics will match that of all the fish in our oceans by 2050.
Sea animals can even die if they eat the plastic in the ocean. Smaller plastic pieces car also enter the food chain（食物链）and end up in our bodies.
Slat’s plan was to create a friendly, large system to move away plastic from the ocean. After trying seven years, hundreds of models and many failures, on Oct 2. 2019, a machine called System 001/B came out. It successfully caught and collected much more plastic in the ocean.
Slat and his team are working to improve system 001/B. Their dream is to clean up 90 percent of all plastic by 2040. “In a few years we will have a full scale-fleet（舰队）out there…” he said in public.
1. While having a holiday in Greece, Boyan Slat finds that _________.| A．it’s difficult to stop ocean pollution |
| B．sea animals die from plastic pollution |
| C．ocean pollution is much better in Greece |
| D．there is too much plastic in the ocean |
| A．ways to reduce the plastic pollution |
| B．the plastic problem is worse than before |
| C．where plastic in the ocean comes from |
| D．what we should do to protect the ocean |
| A．It will come out by 2040. |
| B．It only catches small pieces of plastic. |
| C．It was difficult to create this system. |
| D．It will clean all of the plastic in the ocean. |
| A．A vacation in Greece |
| B．More plastic bags than fish |
| C．Cleaning up the oceans |
| D．A machine called System 001/B |
【推荐2】Okay to Eat?
At least 50% of U. S. adults have eaten food off the floor. That’s according to a 2017 Harris Poll. Many people use the five-second rule. The rule says that fallen food is safe to eat if it has been on the floor for less than five seconds. Can people really use the five-second rule to save a dropped sandwich? Or should they throw it and make a fresh one?
Donald Schaffner is a professor of food science. His study shows that the five-second rule should not always be used. In his 2016 report, he says it’s not wise to eat dropped wet food. The wet food takes in bacteria(细菌) as soon as it falls. “Bacteria don’t have legs, they move with the moisture,” Schaffner says. The wetter the food is, the more bacteria it soaks up(吸收).
Anthony Hilton studied the five-second rule too. He is a professor of Life and Health Sciences. Hilton found that a dry food on the floor collects fewer bacteria than a wet food. Hilton also found that carpeted floors pass fewer bacteria than wood floors. Still, one should be careful. “Food that is on the floor is never completely risk-free to eat,” he says. “But if you drop a dry food in your house, it’s usually okay if you pick it up very quickly. Most clean homes don’t have bad bacteria.”
Should you eat food that was dropped on the kitchen counter? Dr. Steven Dowshen is a doctor for children. He says that floors are not the only place that can make food unsafe to eat. “Kitchen counters can contain more harmful bacteria,” Dowshen told TFK. This is because raw foods sometimes have bad bacteria called salmonella. These raw foods can be on kitchen counters. “If people eat food off a surface that has salmonella, they can get very sick,” says Dowshen.
With the five-second rule, the type of food and the place where it falls matter. So perhaps use this instead: When in doubt, throw it out.
1. What’s Donald Schaffner’s opinion about the five-second rule?| A．The five-second rule should always be used. |
| B．The drier the food is, the more bacteria it takes in. |
| C．It’s a good choice to eat the dropped wet food. |
| D．The minute the wet food falls, it soaks up bacteria. |
| A．delicious | B．dangerous | C．safe | D．easy |
| A．People should not eat a dropped sandwich on any places. |
| B．People cannot eat food that is on the floor because of salmonella. |
| C．People need to consider the type of the dropped food before eating. |
| D．People should be careful about the food dropped on the kitchen counter. |
| A．To introduce the five-second rule to people. |
| B．To encourage people to use the five-second rule. |
| C．To show different people’s opinions about the five-second rule. |
| D．To advise people to think twice before using the five-second rule. |
【推荐3】Children who eat three or more hamburgers a week are more likely to suffer from asthma（哮喘）, researchers say. However, they say that the risk may not be caused by the meat-rich diet（饮食）itself, but by a lack of fresh fruit and vegetables.
The study looked at 50,000 children from 20 countries. Parents were asked about their children's eating habits and whether they had ever suffered from asthma. The effects of their diet seemed to be different depending on where they lived. Fruit and vegetables are more helpful in less affluent parts of the world, while eating lots of fish was more helpful in richer countries. Eating at least three hamburgers a week was linked to（与……有联系）a greater risk of asthma, but only in wealthier countries.
Dr Gabriele Nagel said different things may cause asthma in different parts of the world. “This gives us more understanding of how asthma affects（影响）different people, and its effects in developing countries as well as developed countries,” she said.
High levels of unhealthy fat in hamburgers could increase the risk of asthma. However, the researchers said children who ate several hamburgers a week were likely to have other unhealthy lifestyle habits as well.
Researchers said the study helped us understand how asthma and diet are connected. “Previous studies have shown that a diet rich in fruit and vegetables can help to reduce a child's risk of developing asthma symptoms,” Dr Elaine Vickers said. “Our advice to parents is to make sure that children have a healthy diet and also get plenty of exercise.”
1. What can we learn about the study from the passage?| A．The fat in hamburgers doesn't increase the risk of asthma. |
| B．Children who like hamburgers don't like exercise. |
| C．Eating three hamburgers a month could cause asthma. |
| D．The parents of fifty thousand children were interviewed. |
| A．warm | B．healthy | C．rich | D．dangerous |
| A．Fruit. | B．Fish. | C．Vegetables. | D．Meat. |
| A．To help children have a healthy lifestyle. |
| B．To keep children away from hamburgers. |
| C．To have dinner with children at home. |
| D．To make sure children take much exercise every day. |
| A．how asthma affects people in wealthy places | B．why hamburgers raise a child's risk of asthma |
| C．how parents can influence children's study | D．why more and more children become fatter |
