Doctors sometimes prescribe light therapy to treat a form of depression in people who get too little morning sun. But too much light at other times may actually cause such mood disorders. Long-lasting exposure to light at night brings depression, a new study finds, at least in animals. The new data confirm observations from studies of people who work night shifts, says Richard Stevens of the University of Connecticut Health Center. Mood disorders join a growing list of problems, including cancer, obesity and diabetes--that can occur when light throws life out of balance by disturbing the biological clock and its timing of daily rhythms. www.ks5u.com In the new study, Tracy Bedrosian and Randy Nelson of Ohio State University exposed mice to normal light and dark cycles for four weeks. For the next four weeks, half of the mice remained on this schedule, and the rest received continuous dim light throughout their night. Compared with mice exposed to normal nighttime darkness, those getting dim light at night lost their strong preference for sweet drinks, "a sign they no longer get pleasure out of activities they once enjoyed, " Bedrosian says. In a second test, mice were clocked on how long they actively tried to escape a pool of water. Those exposed to night lights stopped struggling and just floated in the water, a sign of "behavioral despair",10 times as long as the mice that had experienced normal nighttime darkness. All symptoms of depression disappeared within two weeks of the mice returning to a normal light-dark cycle, the researchers report. The scientists also could quash the behavioral symptoms by injecting the brains of animals with a drug that prohibits the activity of certain molecules linked with human depression. This finding further suggests that light at night may cause something related to depression. Human studies linking nighttime light and mood disorders are important but can't easily detect molecular underpinnings as animal studies can,says George Brainard of Thomas Jefferson... What is the main idea of the passage? A) Nighttime light may foster depression. B) A drug has been found to cure mood disorders. C) The study on animals can be applied to humans. D) Human biological clock can be controlled by light.
A
Unknown to most Facebook users, the social network actually offers a lot of privacy controls and security features which can help you lock your account, so you can speak freely. If it's used properly, you'll never have to worry about whether you will have to "friend" your boss or your mom. You can friend anyone you want while staying comfortable in the knowledge that not everyone gets to see everything you post. The problem with carrying out these privacy options is that they're just too confusing for most non-tech clever people to handle. And often, most people don't want to bother to take the time to learn. To simplify the process, we're offering one easy step you can take today to help make your Facebook experience safer, more secure, and more private. Just make "Friend Lists". Yes, it will take some time, especially if you're connected to a couple of hundred friends already. But this step, while not the quickest, is fairly simple. And it will be one of the most useful things you can do on Facebook. Friend lists, as the name suggests, are lists for classifying your friends into various groups. The nice thing about this feature is that once you set these lists up, you won't have to do it again. We suggest that you put your work colleagues and professional acquaintances into a friend list named "Work", personal friends you're not very close with into a list called "Acquaintances", and people you're related to into a list called "Family". Those three main categories will separate out the groups of "friends" who you may want to hide some information from. To create a friend list, click on "Friends" at the top of the Facebook homepage. In the left-hand column, click "Friends" again under the "Lists" section. Now you'll see a button at the top that says "Create New List". Click it. In the pop-up that appears, you can name your list and pick members. If you've ever shared an application with your friends, the process of doing this will be very familiar. When you've finished making lists, you'll be able to use... What can we learn about Facebook according to the text? A) Its process of privacy-setting is too complex. B) It displays everything people post. C) It lacks privacy controls and security features. D) Its post is designed for technical people.
A
Q: A recently study found people's lives are made shorter in North China. It is showed the life expectancy had been cut down by 5.5 years there. Researchers think that the heavy air pollution in China should be to blame . It's really the truth. Our government has already done something. However, it doesn't seem to work so well. "Air pollution in China is doing harm to people's health. The harm is much more serious than we can imagine," said Chen Yuyu of Beijing University, one of researchers of this study. Dirty air brings serious problems in North China. In January this year, the air pollution was worse than that in other places. That was caused by rising temperature and waste gas from coal heating. Chinese government should strongly fight against air pollution. They should think of more proper ways to deal with the problem. People should be encouraged to take buses, ride bicycles or walk, instead of driving cars. The factories that pollute heavily should be closed. "We need to improve our environment, although it might be expensive. Protecting our environment means protecting ourselves," Li Hongbin, another researcher of the study said. The passage above may come from a(n) _ ? A) story B) advertisement C) report D) diary
A: C
Q: As you are students of English, it's very possible that you'll be interested in England. That's where the language was first spoken. But England is often called by other names. This often confuses people and I wonder if you know what these names mean. So, now I would like to tell you about this matter of names. I believe that you have heard people use the names--England, Britain or Great Britain. Let's see what each of these names means. If you look at a map of Europe, you'll see a group of islands--one larger island off the northwest coast, one smaller and many tiny ones. These make up what is called the British Isles. The largest island of the British Isles is Britain. It is also called Great Britain. The smaller island is Ireland. Britain is divided into three parts: Scotland, Wales and England. But sometimes the word "England" is used instead of "Britain". Why so? In ancient times, what is Britain now used to be three different countries. People in these different countries spoke different languages. Over many years the three countries became one. England is the largest and richest of the three and it has the most people. So the English people take it for granted that their own name stands for the whole island. There's another thing that confuses people: sometimes you may hear people say "the United Kingdom of Great Britain and Northern Ireland". That is the official name of the country. Northern Ireland is only one sixth of the island of Ireland. The rest of the island is an independent state, called the Republic of Ireland. So we have the names of "England", "Britain", "Great Britain", and "the United Kingdom of Great Britain and Northern Ireland". Now do you know what each of them means? Which of the following is the best title? A) Students of English B) Different Names of England C) Different Languages Spoken in England D) The Republic of Ireland
A: B