Read the article and select the best answer. Article: Lights Out at Bedtime There are plenty of good reasons to power up a personal desktop or laptop computer in the evening -- writing e-mails,chatting on social networks or making purchases over the Internet,for instance.But various studies indicate that people who stare at a PC's bright monitor shortly before going to bed probably sleep less soundly than they would otherwise because the light seriously affects their natural wake-sleep cycle."They haven't proved it though," says Dieter Kunz,the team's director at Charite's Psychiatric Clinic in St.Hedwig's Hospital in Berlin. Similarly,exposure to just 10 minutes of normal bathroom lighting is enough to free the sleep hormone melatonin,which regulates people's natural wake-sleep cycle and makes them sleepy at nightfall. Ten years ago,a team of British and American researchers detected a photo-pigment in the human eye that signals to the body whether it is day or night,summer or winter.The photo-pigment is especially sensitive to blue light. "The blue light more or less tells the body,'It's daytime,be awake,'" Kunz says.Monitors have a mostly cold white light content and scientists suspect the photo-pigment may react similarly to it.So the longer people look into the bright light,the more awake they become - and then sleep poorly. A lot of people have difficulty "switching off" in the evening.About half of the women in Germany and a quarter of the men sleep poorly. Environmental factors are only one of the possible causes.Job stress as well as personal and health concerns are also the main reasons for their sleep problems. In addition,electronic objects' standby lights and indicator lamps can be annoying in the dark and affect sleep."Sound scientific evidence is still lacking on this matter," Kunz notes. According to Kunz,those who cannot go without their computer in the evening should turn down the blue content if possible and lower the brightness somewhat."But nobody does that because,after all,you want to concentrate while working at the computer and the... Question: We can learn from the passage that _ . Options: A: the blue light has a calming effect. B: the photo-pigment tells people day or night C: women in Germany use computers more often than men D: it has been proved that standby lights affect people's sleep
B

Read the article and select the best answer. Article: Are you an early riser or a night owl? Researchers from Aachen University in Germany believe that about 10 percent of people can be classified as "morning people", who feel more active and function best in the morning.Around 20 percent are night owls--people who naturally tend to stay up late and are more tired during the day.And the rest of us fall somewhere in between, according to New Scientist. Previous studies have suggested that early risers are more likely to be happy and healthy while night owls experience worse sleep as well as more depression and anxiety during the day. For a long time, scientists have been trying to find out what causes the differences between the two.A new study suggests that it isn't just people's habits--early risers and night owls actually have different brain structures. Led by Jessica Rosenberg at Aachen University, researchers scanned the brains of 16 early risers, 23 night owls and 20 people with intermediate sleeping hours.They found that the brains of night owls had less "white matter"--which speeds up the transmission of nerve signals -- in brain areas associated with depression. As you know, after people fly in an airplane from one time zone to another, they often suffer from a confused and tired feeling called "jet lag" because their body clocks are out of sync with the new time zone.It usually takes about a week for their bodies to adjust to the new time.But night owls always have difficulty syncing their bodies to the right time due to their brain structure."It's like they suffer from permanent jet lag," said Rosenberg. The good news is that it is possible for night owls to turn themselves into morning people.According to the researchers, night owls should try to spend as much time in the sunlight as possible and reduce their exposure to artificial light at night to force their body clocks to shift to a more normal rhythm. Question: What does the article mainly discuss? Options: A: How to turn early risers into night owls. B: How our habits influence our sleep patterns. C: What causes the differences between early risers and night owls. D: Why early risers are happier and healthier than night owls.
C

Q: Read the article and select the best answer. Article: Jiang Nan, a full-time mother in Beijing, keeps a dozen or so cloth bags at home, carefully selecting one or two before heading out to get groceries. "Most of them were giveaways from advertising marketing campaigns, but others had been handed out in the street by various environmental protection organizations," she explained. Since June 2008 China has forbidden the production, sale and usage of plastic bags thinner than 0.025 millimeter , and retailers are not allowed to provide free plastic bags to their customers, no matter how thick they are. Many Chinese consumers like Jiang have learned to refuse plastic bags whenever possible in their shopping. "A plastic bag may only cost a few jiao, but it's more about how bad they are for the environment," Jiang said. The plastic ban is for the most part well carried out in big cities, and has been obviously effective in reducing white waste. On the first anniversary of the plastic ban Global Village of Beijing, an NGO environmental organization, shows that during the year of the ban the consumption of plastic bags fell by about 40 billion pieces in chain supermarkets alone, saving more than 1.2 million tons of petrol. However, enforcement shows rather less muscle in smaller cities, towns and countryside. In a remote town like Lichuan, the awareness of environmental protection is not as strong as that in big cities. Street vendors worry that they are likely to lose customers if they charge them for plastic bags. Seeing no significance in the issue, local government often turn a blind eye to banned bag trade in the market. There are still those who don't have an interest in living green. Cui Lin, another Beijinger, often forgets to bring a cloth bag when shopping, and has to buy plastic bags. "Anyway I think plastic bags are neater and cleaner, and I don't mind paying a couple more jiao," he shrugged. Mrs Yu, a vegetable vendor in Lichuan County, Jiangxi Province, recalled that before plastic bags became popular in the early 1990s, Chinese people always... Question: What message does the writer mostly convey in the passage? Options: A: To reduce white waste is urgent. B: The plastic bag ban has achieved great success. C: There is still a long way to go for the plastic bag ban. D: People's awareness of environmental protection should be stressed.
A: C