Sitting on exercise balls brings more than a smile to students and teachers.Some fourth-gr

Sitting on exercise balls brings more than a smile to students and teachers.
Some fourth-graders at Conrad Weiser West Elementary School in Womelsdorf love their new chairs-—probably because they're not really chairs at all.
The kids are sitting on the air-filled balls. But different from those just for exercise, these have small legs that keep them from rolling. Sitting on a chair all day in school can make anyone want to move around. So, more and more teachers are letting students have a ball. By using exercise balls instead of common chairs, teachers find students' posture(姿势) and attention improved.
Dotti Pownall, a fifth-grader teacher in West Virginia, has been using balls as chairs since December 2008. The students love them. she says. Pownall took a survey of her students. She found that 80 percent, thought sitting on the balls helped them concentrate(专注) better:
Besides, they’re fun,b says Pownall.
According to WittFitt,b a company that has sold balls to more than 200 schools, they can improve kids' posture and classroom behavior.
Exercise ball chairs are getting popular in classrooms, from preschool to college. Some adults (成人) even use them at work.
Lisa Witt felt so strongly about the use of balls as chairs that she started WittFitt. She said the company not only encourages the use of balls but also educates teachers and students on how to use them. We sell balls in 24 states in America, three provinces in Canada and Japan. says Witt.
【小题1】Sitting on exercise balls can .A．improve students' attentionB．make students smarterC．keep students moving around D．help students become fit【小题2】According to the passage, the company WittFitt .A．began to produce balls in 2008 B．sells balls in 24 countries C．was set up by Lisa WittD．is famous around the world【小题3】It can be seen from the passage that .A．exercise balls have no legsB．Pownall works as a teacherC．students hate exercise balls D．exercise balls are filled with sand【小题4】The passage mainly tells us about .A．the shape of exercise balls B．the use of exercise balls C．the number of exercise balls D．the inventor of exercise ballsA

(答案→)A 解析：【主旨大意】本文介绍了美国人发明的一种新型椅子—运动球椅的用处：这种椅子不仅能纠正学生的坐姿，而且还能提高学生的注意力，因此备受学生和老师的青睐。【小题1】细节理解题。根据第三段最后一句“By using exercise balls instead of common chairs, teachers find students' posture and attention improved.”可知答案选A。【小题1】细节理解题。根据最后一段第一句“Lisa Witt felt so strongly about the use of balls as chairs that she started WittFitt.”可知，Lisa Witt 创建了这家公司。【小题1】细节理解题。根据第四段第一句“Dotti Pownall, a fifth-grader teacher in West Virginia,...”可知， Pownall是一名教师。【小题1】主旨大意题。纵观全文，都在围绕运动球椅的好处这个话题来介绍的。

就是这个解释