题目内容：

If you think English means endless new words, difficult grammar and sometimes strange pronunciation, you are wrong. Haven’t you noticed that you have become smarter since you started to learn a language?

According to a new study by a British university, learning a second language can lead to an increase in your brain power. Researchers found that learning other languages changes grey matter. This is the area of the brain which processes information. It is similar to the way that exercise builds muscles.

The study also found the earlier people learn a second language, the greater the effect is.

A team led by Dr. Andrea Mechelli, from University College London(UCL), took a group of Britons who only spoke English. They were compared with a group of “early bilinguals(通两种语言的人)”, who had learnt a second language before the age of five,as well as a number of later learners.

Scans showed that grey matter density in the brain was greater in bilinguals than in people without a second language. But the longer a person waited before mastering a new language, the smaller the difference was.

“Our findings suggest that the structure of the brain is changed by the experience of learning a second language,” said the scientists.

It means that the change itself increases the ability to learn.

Professor Dylan Vaughan Jones of the University of Wales, has researched the link between bilingualism and maths skills.

“Having two languages gives you two windows on the world and makes the brain more flexible,” he said, “You are actually going beyond language and have a better understanding of different ideas.”

The findings were matched in a study of native Italian speakers who had learned English as a second language between the ages of 2and 34.Reading, writing and comprehension were all tested. The results showed that the earlier they started to learn, the better. “Studying a language means you get an entrance to another world,” explained the scientists.

1. What does the underlined part “grey matter” (in Paragraph 2) refer to?

A．Grey hair.	B．Material of the brain.
C．Intelligence.	D．Difficult situations.

2. The experience of learning a second language can ________.

A．change one’s brain completely	B．improve one’s maths skills
C．make one smarter than others	D．increase the ability to learn

3.We can learn from the passage that ________.

A．the researchers from UCL did another study in Italy

B．a similar study was done on native Italian speakers who learn English as a second language

C．the research done on the Italians showed a totally different result

D．it will be easier for one to travel around the world by learning a second language

4.What’s the main idea of the passage?

A．Learning a second language can help improve your brain power.

B．You should learn a second language that is not your native language.

C．If you want to learn a second language, you should do it at a certain age.

D．The research done by the researchers from UCL is very successful.