In the United States, elementary and middle schools are advised to give students two and a half hours of physical activity a week.
Yet many schools across the country have reduced their physical education programs. Criticism（批评） of the cuts has led in some places to efforts to give students more time for exercise, not less.
A study reported that life expectancy（寿命） has fallen or is no longer increasing in some parts of the United States. The situation is worst among poor people in the southern states, and especially women. Public health researchers say it is largely the result of increases in obesity（肥胖）, smoking and high blood pressure. They also blame differences in health services around the country.
A study found that only four percent of elementary schools provided daily physical education all year for all grades. This was true of eight percent of middle schools and two percent of high schools. The study also found that twenty-two percent of all schools did not require students to take any P.E.
Charlene Burgeson is the executive director of the National Association for Sport and Physical Education. She says one problem for P.E. teachers is that schools are under pressure to put more time into academic subjects. Also, parents may agree that children need exercise in school.
But experts say P.E. classes have changed. They say the goal has moved away from competition and toward personal performance, as a way to build a lifetime of activity. These days, teachers often lead activities like weight training.
Some parents like the idea of avoiding competitive sports in P.E. class. Yet others surely dislike that idea. In the end, schools may find themselves in a no-win situation.
. How many reasons have caused some Americans’ life expectancy to fall?

A．Three.

B．Four.

C．Five.

D．Six.

 The underlined part “that idea” (the last paragraph) refers to _______.

A．competitive sports	B．a lifetime of activity
C．no-win situation	D．uncompetitive exercise

. From the passage we can infer that _______.

A．physically active children have more chances to be fit when growing up

B．most American schools let students take physical activity enough

C．the older a student is, the less exercise he gets

D．not all parents think exercise is good for students

. The passage mainly tells us about _______.

A．school and students’ health	B．how to make children healthy
C．American schools’ physical education	D．American students’ health