题目内容：

What should you take in with you when you take an exam? Pen, pencil, eraser, ruler..., and don’t forget a bottle of water!

According to a study at the British Psychological (心理学的) Society Annual Conference held in London, if students bring water into exams, they may improve their grades by up to 10 percent.

Scientists at the University of East London and the University of Westminster, UK, did a study on 447 students. Only 25 percent of them brought something to drink to the exam hall.

Scientists then compared their exam results with their normal schoolwork grades. They found that all those who had brought drinks with them got better grades by 2 to 10 percent.

It is unclear why drinking water improves exam results. But scientists say having enough water in our bodies could have a helpful influence on our brains. Drinking water may also cut down on anxiety(焦虑) , according to Chris Pawson, PhD, of the University of East London.

"Whatever the explanation, it is clear that students should try hard to stay hydrated(含水的)with water during exams," he said.

So next time, when you are going to have a big exam, try bringing a bottle of water with you. Who knows - it may help you pass the exam!

1.If the students bring water into exams, their grades may be improved         at most.

A. by 2%          B. by 8%

C. by 10%        D. by 25%

2.The underlined phrase "cut down on" probably means        .

A.增加            B.带走              C减少                D.改变

3.According to the passage, how does water help students in exams?

A. It is good for their brains.

B. It makes students smarter.

C. It helps students feel full.

D. It makes students feel nervous.

4.You probably read the article from a       .

A. sports magazine   B. textbook

C. travel guide        D. newspaper