题目内容：

    Sitting on a chair all day in school can make anyone want to move around.So more and more teachers are letting stidents have a ball.By sitting on exercise balls instead of chairs，teachers find students' attention improve.

Peter，a fifth-grade teacher in West Virginia，the USA，has been using balls as chairs since December 2010.“The students love them"，he says.Peter took a survey of his students.He found that 80% of the students thought sitting on the balls helped them pay more attention to what they were learning.

The manager（经理），Mary，felt so strongly about the use of balls as chairs，she encourages the use of the balls.She hopes not only teachers but also students know how to use them.“Our products（产品）are used in 24 states（州），three provinces（省）in Canada，Puerto Rico and Japan，"says Mary."Research（调查）shows that sitting on the balls makes them sit up straighter，”says Mary，"but it feels not boring."Because the students are moving，so the kids have more energy and can keep longer.

“Besides，they're fun.”says Peter.

1.What will happen if a student sits on a chair all day in school？The student will____

A. pay more attention to his lessons B. be fun

C. like to move around D. sit up straighter

2.How long has Peter used the balls?

A. About five years. B. Only one year.

C. About 8 years. D. Since he was a fifth-grade teacher.

3.In how many countries are the balls used as the students' chairs?

A. Four. B. Three C. Two. D. One.

4.Teachers choose balls instead of chairs because sitting on balls helps the____.

A. improve the students'posture and attention

B. slouch（没精打采地坐着）on the chairs

C. have fun

D. Both A andC

5.Which is better for kids to study in class，sitting on a chair or sitting on a ball？

A. Sitting on a chair. B. Sitting on a ball.

C. They are the same. D. We don't know.