Ques: Read the article and select the best answer. Article: There was good news last week for people who struggle to get eight hours of sleep a night: they may not need so much shut-eye after all. Researchers from UCLA and elsewhere looked at sleep habits of remote hunter-gatherers in Tanzania, Namibia and Bolivia -- groups with pre-industrial lifestyles whose sleep patterns are believed to reflect those of ancient humans. The researchers found that, on average, members of each group sleep a bit less than six and a half hours a night. The study, published in the academic journalCurrent Biology, indicates that "natural" sleep is less than eight hours a night and that modern society's numerous electronic distractions aren't necessarily to blame for people getting just six or seven hours of sleep. "The story that often gets out is that if you sleep for less than seven hours, you're going to die early," he told me. "That's not true." Yet Americans are addicted to getting more sleep -- and on turning to medical shortcuts to help them. According to the Centers for Disease Control, as many as 70 million U.S. adults suffer from sleep disorders or sleeplessness. Only a third of Americans get the government's recommended seven to nine hours of sleep a night. About 9 million American adults use sleeping pills to help get a good night's rest, the CDC found. Siegel said the number of people relying on medicines "has gone up rather rapidly since then." Industry consulting firm GlobalData estimates that worldwide sales for sleeplessness medicines will run about $1.4 billion next year and reach $1.8 billion by 2023, recovering from lower sales in recent years because of cheaper generics hitting the market. Dr. Roy Artal, a sleep specialist in West Los Angeles, said it's understandable that busy people in today's go-go world would turn to medicines to speed up the sleep process. But all they're doing is building a reliance on powerful drugs for relatively little improvement. "There's no magic pill that makes us sleep when we want and wake up when we want," Artal said. "The effects... Question: The main idea of this passage is that _ . Options: A: people may not need eight hours of sleep a night B: people need sleeping pills to have a good sleep C: sleeping pills have a long way to go for sleep improvement D: sleeping pill industry will suffer great losses from the new discovery
Ans: A

Ques: Read the article and select the best answer. Article: Sir John a British scientist who won last year's Nobel prize for medicine, said he had predicted at the time of his frog experiments that the successful cloning of a mammal would happen within 50 years.and that "maybe the same answer is appropriate" far the step to human cloning. Parents who lose children in accidents may be able to clone "copies" to replace them then. Although any attempt to clone an entire human would raise complex moral issues, the biologist claimed people would soon overcome their concerns if the technique became medically useful.Cloning was regarded with extreme doubts when it was first developed but became widely accepted after the birth of Louise Brown, the first "test tube baby" He said, "When my first frog experiment.s were done, an American reporter asked how long it will be before these things can he done in mammals or humans I said, 'Well, it could be anywhere between 10 years and 100 years-how about 50 year ?' It turned out that it wasn't far off the mark as far as Dolly was concerned.Maybe the same answer is appropriate." Sir John added that cloning a human being effectively means making an identical twin, and doctors would therefore simply be "copying what nature has already produced" The average vote on allowing parents of deceased children, who are no longer fertile , to create another using the mother's eggs and skin cells from the first child, thinking the technique was safe and effective, is 60 per cent in favor.The reasons for "no" are usually that the new child would feel they were some sort of a replacement for something. . Question: Sir John predicted the human cloning would be a reality in _ at most. Options: A: 100 yea B: 60 years C: 50 years D: 10 years
Ans: C

Ques: Read the article and select the best answer. Article: Nowadays, there is a heated debate on whether pollutants should be cleaned in the air. Cleaning up the air, while good for our lungs, could make global warming worse. And the pollutants still go up around the air, along with carbon dioxide. These pollutants are called aerosols and they include soot as well as mixtures of nitrogen and sulfur and other stuff into the air. Natalie Mahowald, a climate researcher at Cornell University, says so far, scientists have mostly tried to understand what those aerosols do while they're actually in the air. "There are so many different kinds of aerosols," she says. "Some warm and some cool. But in fact, humans are giving out a lot of extra aerosols, and they tend to cool for the most part." The aerosols reflect sunlight back into space, or keep us cool. But it turns out that's not all they do. These aerosols also influence how much carbon dioxide gets drawn out of the air by plants on land and in the sea. "They can add nutrients, for example, to the oceans or to the land," Mahowald says. "But also while they're in the atmosphere they can change the climate, and thus that also can influence the amount of carbon, the land or the ocean can take up. So there are quite a few different ways that aerosols can act on each other." Mahowald's results suggest that reducing those pollutants could be an even bigger problem than realized, when you consider that aerosols help remove carbon dioxide from the air by encouraging plant growth. Hard numbers on this effect are highly uncertain at the moment, but this could turn out to be quite significant. And studying it is not easy because the effects aren't well understood. For example, nitrogen can be a fertilizer , but it can stop plant growing when nitrogen comes out of the air in acid form. Right now it seems like we're much more likely to clean up aerosol pollution, while increasing the amount of carbon dioxide in the air. So scientists, unfortunately, may have a chance to see whether this experiment on our planet should continue or not. Question: Why is it important for scientists to get accurate numbers according to the passage? Options: A: Scientists have a chance to research them. B: They can bring scientists much more benefit. C: Scientists can protect the earth from being polluted D: They can help scientists understand the effects better.
Ans:
D