1 . China has just officially opened its FAST radio telescope to international scientists. Scientists across the world can submit proposals for astronomical observations using the telescope.
FAST is short for Five-hundred-meter Aperture Spherical Telescope (球面射电望远镜) and it is also believed to be the world's largest radio telescope and the most sensitive single-dish radio telescope. The receiving surface area of FAST is 250,000 square meters, about the size of 30 standard football fields. Its construction was completed in September 2016 and it officially began operating in January 2020.
The major scientific task of the telescope is the observation of pulsars (脉冲星) – the rotating neutron stars. The study of pulsars can help to confirm the existence of gravitational radiation and black holes, and help solve many other major questions in physics. Another scientific goal of FAST is to search for outer space civilization.
The telescope is located in a naturally deep and round karst depression in southwest China's Guizhou Province. The first advantage of the selected site is the altitude. The average altitude of Guizhou is about 1,100 meters, which maximizes the effectiveness of the observation equipment. Secondly, the radio telescope needs to have a “big pan” to receive better signal. The huge natural depression could reduce the amount of excavation (挖掘) and difficulty of construction. Moreover, the selected site in Guizhou is far away from cities, and has a small population, which reduces the interference (干扰) caused by wireless devices such as TVs, mobile phones and radios from human activities.
FAST has identified over 300 pulsars. Experts predict that the number could reach 1,000 in five years and that the telescope could locate and identify the first pulsar outside the galaxy. With the opening-up to international scientists, China's FAST is expected to make more contribution to astronomical research in the future.
1. What do we know about FAST?| A．It is opened to global scientists. | B．It is a project under construction. |
| C．It has provided service since 2016. | D．It has found a pulsar outside the galaxy. |
| A．To study black holes. | B．To observe the pulsars. |
| C．To explore the sun. | D．To seek space civilization. |
| A．It's close to urban areas. | B．It reduces engineering amount. |
| C．It possesses a shallow depression. | D．It's at the highest altitude in China. |
| A．Major Scientific Tasks of FAST | B．Ways to Select the Site for FAST |
| C．Contributions FAST Has Made | D．Facts about FAST Radio Telescope |
2 . New parents who clean their homes very often to protect their babies from bacteria and other organisms might cut back their efforts.
A new study suggests high levels of contact with cleaning products are linked to an increased risk of the childhood breathing condition known as asthma (气喘).
Researchers asked a group of parents how often they used 26 common household cleaners during their babies’ first three to four months of life. By age three, the children who had come in contact with cleaning products the most were more likely to be diagnosed with asthma. The researchers said children who had a lot of contact with cleaners were 37 percent more likely to have asthma than children with the least contact. The study also found a lot of exposure to cleaning products caused children to be 35 percent more likely to have chronic difficulty breathing. In addition, they were 49 percent more likely to have chronic allergies.
Tim Takaro, who helped lead the study, suggested that parents should question the belief that their home is clean only if it smells like chemical-based cleaning products. He also advised them to look for products free of substances like chemical colors. Besides, they should consider natural cleaning products instead of chemical ones.
The American lung Association recommends avoiding cleaning products that contain volatile (易挥发的) organic substances and other irritants (刺激物). But companies in Canada and the United States are not required to list all the chemicals in cleaning products. Some products labeled as environmentally friendly, or "green", may contain harmful substances.
Elissa Abrams, a doctor with the University of Manitoba, admitted the effects of cleaning products are not well understood. But she believed these products and the chemicals they contain act as irritants to growing children "The take-home message is that parents should be careful with cleaning products they use in the home", she added.
1. What is the third paragraph mainly about?| A．The suggestions on using cleaning products. |
| B．The parents’ opinions of household cleaners. |
| C．The conduct of the study and the findings. |
| D．The reason for using cleaning products. |
| A．Have a full understanding of cleaning products. |
| B．Keep their home free of all kinds of cleaning products. |
| C．Use natural cleaning products rather than chemical ones. |
| D．Make their homes smell like chemical-based cleaning products. |
| A．They are environmentally friendly without any harm. |
| B．They are asked to list all the chemicals contained. |
| C．They are free of irritants if labeled "green". |
| D．They are not always safe to be used. |
| A．Arts & Culture. | B．Lifestyle & Health. |
| C．Life & Technology. | D．Climate & Environment. |
3 . My work started in 2003 at my local animal shelter’s Adoption Department. It seems like such a long time ago. In the 13 years that have passed, more than 50,000 animals have passed the doors of the shelter. Most of them, I do not remember. But occasionally there are animals who stand out. Tabby was one such animal.
Tabby was one of the many homeless dogs. What’s more, she was blind and deaf. Tabby’s chances at adoption seemed remote at best. But one day a woman named Loretta came to the shelter. Her son, Gary, who suffered from epilepsy (癫痫) had seen Tabby’s picture on the shelter’s website. They were interested in meeting her! Most boys would want a puppy, a dog who could grow with him and run through grassy fields on summer days. Tabby would never be able to do that. But as they say, "love is blind". After meeting her, they decided to adopt Tabby!
If Tabby’s story had simply ended with her successful adoption, it would still have been something very special indeed but it was what happened after her adoption that some might label as "magical" or perhaps even miraculous. As Gary and Tabby did everything together, they became so "in tune" with one another that Tabby began to telegraph Gary’s seizures (疾病发作) before they occurred, giving his family a warning that one was about to strike. What’s more, Gary seemed to be having fewer and fewer seizures since Tabby’s arrival.
How could it be? There are some things that happen in this world that challenge all logic and understanding. Sometimes, the best that we can do is to accept a miraculous thing, which we didn’t attempt to explain. Because when you try to explain it, you lose the beauty and wonder of it all.
1. Which sentence can be used to describe Tabby?| A．She was so lovely that she could be easily adopted. |
| B．She suffered a lot from the disease-epilepsy. |
| C．She was so strong that she could run very fast. |
| D．She was homeless and couldn’t see or hear. |
| A．Amazing. | B．Typical. | C．Interesting. | D．Special. |
| A．Gary learnt about Tabby from a magazine. |
| B．Gary was cured in the company of Tabby. |
| C．Tabby could indicate a seizure before it struck. |
| D．Most boys would have the same decision as Gary. |
| A．Love is Blind: a Miraculous Dog | B．Give Me Food: My Dear Master |
| C．Love is Everywhere: a Poor Dog | D．Take Me Home: My Dear Boy |
4 . Identical twins (同卵双胞胎) may not be exact copies at the DNA level after all. Normally, identical twins differ by 5. 2 genetic changes. Researchers shared their new finding in Nature Genetics.
Identical twins are also called monozygotic twins (单卵双胞胎). They come from a single egg. That egg forms an embryo (胚胎). Then, it splits into two embryos. Each of these embryos will go on to become a baby.
Identical twins have long been thought to have the exact same genes. That's why some scientific studies study these twins. Such studies try to determine whether particular features, diseases or conditions are due to genes or instead reflect environmental influences. Any differences in the health of identical twins were thought to be due to different environmental exposures. The new findings, though, suggest that genetic changes might also explain why identical twins aren't truly identical.
Researchers in Iceland studied 381 pairs of identical twins. Then the scientists studied all the genes in each person carefully. Only 38 pairs of twins had all the same genes. Most twin pairs differed somewhat in their DNA. Those differences likely arose long before birth. It could have happened either just before one embryo split to form two or it could have happened shortly after the split. Some of the twins had many genetic differences. Thirty-nine pairs had more than 100 differences in their genes.
Gene changes, or mutations (突变), seen in the newly studied twins suggest that embryos don’t split neatly in half when twins form. Some twins may arise when a single cell or a small group of cells splits off from an embryo. How many cells each twin originates from may determine how genetically different they are. More uneven splits of the embryo may lead to a greater number of gene differences in the twins.
1. What does the author intend to do in paragraph 1?| A．Make a comparison. | B．Propose a definition. |
| C．Present a conclusion. | D．Raise an argument. |
| A．Some diseases. | B．Education effects. |
| C．The genetic origin. | D．The changes of gene. |
| A．Almost all the twins have no difference in genes. |
| B．Half of twins have more than 100 differences in genes. |
| C．About ten percent of twins share the same genes. |
| D．Gene differences usually occur shortly after the split. |
| A．Some Identical Twins Don't Have the Same DNA |
| B．Many People Have the Exactly Similar Genes |
| C．Not All the Identical Twins Look the Same |
| D．Identical Twins Attract Many Researchers |
5 . March 21 is World Sleep Day. On March 18, the China Sleep Research Society published a “White Paper on Exercise and Sleep 2021”, which explores the relationship between exercise and sleep. The white paper, the product of surveys in 31 provinces, covers many aspects of sleep and sleep quality. It has attracted widespread interest among netizens after its release.
The report shows over 300 million people in China today have sleep disorders, while the proportion of insomnia(失眠症) among people who exercise regularly is only 10 percent. This means the rate of insomnia among the general population is nearly four times higher than those who exercise regularly.
Studies show sleep is essential, as people spend a third of their lives asleep. Yet today more and more people are suffering from insomnia, which causes us to suffer both physically and mentally.
Increased mental stress is one of the major causes of insomnia. Today people generally work more intensely and are under more mental stress, thus causing sleep disorders. Studies show people with higher income are more likely to sleep late because of overtime, and that lawyers, business executives and doctors often nave to stay up late because of overtime work.
In addition, the popularity or electronics has also enriched our nightlife. Some netizens say, “I feel empty if I don’t browse Tiktok or weibo before going to bed. Retaliatory agrypnia(报复性熬夜)is also increasing among younger generation. They say “The only time I have is the time before I go to bed, and as long as I don’t sleep today, the next day will never come. It forms a vicious cycle in which people don’t get enougn sleep at night and feel sleepy during the day.
Decreased immunity, memory loss, obesity, endocrine disruption and increased risk of depression—these are all possible risks of staying up late.
1. What does the report show?| A．Those who exercise regularly less suffer from insomnia. |
| B．People have no insomnia problems. |
| C．People have mental breakdown. |
| D．People prefer to stay up. |
| A．Regular exercise and limited activities in bed. |
| B．Increased mental stress and electronics. |
| C．Food and lifestyle. |
| D．Work environment. |
| A．Memory loss | B．Obesity | C．Depression | D．Exercise |
| A．The mental breakdown related to insomnia. |
| B．The insomnia problems in current society. |
| C．Te tips to improve insomnia problems. |
| D．Students’sleep disorders. |
6 . Researchers at CU Boulder have developed a wearable device that changes the human body into a biological battery. The device is stretchy(弹性的) enough that you can wear it like a ring, sport band or any other thing that touches your skin. It also taps into a person's natural heat-employing thermoelectric generators to change the body's internal temperature into electricity. "In the future, we want to be able to power your wearable electronics without having to include a battery," said Jianliang Xiao, an associate professor at CU Boulder.
The concept may sound like something out of The Matrix film series, in which a race of robots have enslaved humans to harvest their precious organic energy. Xiao and his colleagues aren't that ambitious: Their devices can generate about 1 volt (伏特) of energy for every square centimeter of skin space-less volt per area than what most existing batteries provide but still enough to power electronics like watches or fitness trackers.
Scientists have previously experimented with similar wearable devices, but Xiao's is stretchy, can heal itself when damaged and is fully recyclable-making it a cleaner alternative to traditional electronics. "Whenever you use a battery, you're depleting(消耗) that battery and will, eventually, need to replace it," Xiao said. "The nice thing about our device is that you can wear it, and it provides you with constant power."
Just pretend that you're out for a jog. As you exercise, your body heats up, and that heat will radiate out to the cool air around you. Xiao's device captures that flow of energy rather than let it go to waste. "The thermoelectric generators are in close contact with the human body, and they can use the heat that would normally be sent into the environment," Xiao said.
1. What does Xiao expect of his device at present?| A．It will be used for medical purposes. |
| B．It will be made smaller and wearable. |
| C．It will change natural power into electricity. |
| D．It will supply constant power to wearable devices. |
| A．To give an explanation. | B．To make a comparison. |
| C．To introduce a topic. | D．To analyze the cause. |
| A．The strengths of Xiao's device. |
| B．The convenience of using a battery. |
| C．The replacement of wearable devices. |
| D．The development of traditional electronics. |
| A．It operates with plenty of power. |
| B．It is designed for practical use. |
| C．It benefits people's health in a way. |
| D．It's based on traditional electronics. |
