Read the following article and select the best answer. Article: She's not afraid of anything. Snakes? No problem. Walking alone in the dark? Easy. We're not talking about a superhero here -- SM is a 44-year-old mother. And she's fearless because she happens to be missing part of her brain: the amygdala . Shaped like a pair of almonds sitting in the middle of your brain, the amygdala helps control fear and anxiety. A rare condition called Urbach-Wiethe disease left SM without her amygdala, and seems to have completely erased her sense of fear. To try to understand how the amygdala works, a team of researchers made their efforts to scare SM. They showed her horror movies and took her to the Waverly Hills Sanatorium Haunted House in Kentucky. She pushed out one of the monsters and laughed. SM said she didn't like snakes, but at a pet store full of poisonous creatures, she kept asking to touch them. When asked to rate her feelings, SM reported feeling surprised or disgusted, but never fearful. "She tends to approach everything she should be avoiding," says Justin Feinstein of the University of Iowa. This means the amygdala could control deeper urges to approach or avoid danger. Other scientists have a different opinion, though. "I don't believe you can make a general statement about what the amygdala does by a single case study," Elizabeth Phelps said. In 2002, Phelps published a study on a similar patient with amygdala damage who still showed fear. It may sound like fun to be totally fearless, but we get scared for a good reason. "The nature of fear is survival and the amygdala helps us stay alive by avoiding situations, people, or objects that put our life in danger," Feinstein said. SM was once followed in a park after dark by a man with a knife, and she simply walked away. "It is quite remarkable that she is still alive," said Feinstein. Question: SM dares to walk alone in the dark mainly because _ . - she is a superhero - she has experienced such conditions a lot - she is a mental patient - she has no sense of fear
she has no sense of fear

Read the following article and select the best answer. Article: Before you go to another country, it is a great help if you know the language and some of the customs of the country. When people meet each other for the first time in Britain, they say "How do you do?" and shake hands . Usually they do not shake hands when they just meet or say goodbye. But they shake hands after they haven't met for a long time or when they will be away from each other for a long time. Last year a group of German students went to England for a holiday. Their teacher told them that the English people hardly shake hands. So when they met their English friends at the station, they kept their hands behind their backs. The English students had learned that Germans shake hands as often as possible, so they put their hands in front and got ready to shake hands with them. It made both of them laugh. Question: It is _ if you know the language and some of the customs of the country. - not useful - not helpful - very helpful - very bad
very helpful

Read the following article and select the best answer. Article: To live forever was the dream of many emperors in ancient China.People were ordered to call them Wansui,which means 10,000 years,but no human could live that long.How long can humans really live? According to the latest scientific discovery,humans are able to live up to the age of 120 or perhaps even longer. Several recent studies showed that our life span can be extended far beyond normal limits.Cynthia Kenyon,a professor at the University of California in San Francisco doubled the life of a worm from two weeks to a month.By changing the function of a single gene,known as daf-2,the scientist not only added extra days to the worm's life but also kept it a healthy as worms which were half its age. There are two similar genes in the bodies of mammals.By changing the function of on gene,scientists extended the life of a mouse by 1 8 per cent(or 4.5 months).Another gene is called IGF-1.Researchers still don't know how it affects our body.But by reducing its functions the life of a mouse increases by 33 per cent for 8.6 months).The average life span of a mouse is 26 months. In the experiment of extending life,an ancient saying,"you are what you eat." also seems to be true.Vegetables contain fewer calories than meat,and help to prolong life,scientists say. Research has found that taking in fewer calories affects our lives in a similar way to reducing IGF-1. US biologist John Phelan suggests low calorie diets could increase human life span,but there is no proof yet. Researchers are still waiting for the results of a study started in 1987.Monkeys are fed with low calorie food to see what happens.A monkey's typical life span is 40 years,so there is a little while to wait. In China,average,life expectancy has now reached 70,double that of 1949. Increasing the length of our lives may bring us closer to the dreams of our ancient emperors.But it may also cause social problems such as housing and employment,social scientists have warned. Question: What is the main idea about this passage? - We are able to live longer. - The genes affect life span of human beings. - A balanced diet prolongs our life. - Extending life span has caused terrible social problems.
We are able to live longer.