Nine out of ten U.S. high school students aren’t getting enough exercise, according to a recent study. Colorado State University (CSU) professor Kaigang Li researched the fitness and exercise habits of kids in their late teens. Rather than depending on surveys to get data (数据), Li asked the students in the study to wear accelerometers-devices (设备) that measure the amount (量) of physical activity — so that he could know how much daily exercise the teens were getting. According to the Centers for Disease Control’s (CDC) recommended (推荐) daily amount of exercise for kids to stay healthy, Li found that 91 percent of the 15-to-18-year-olds did not meet the requirements.

Earlier studies have shown that the amount of daily physical activity is likely to go down from childhood to late teenage years. For example, only 0.04 percent of 9 year-olds exercise less than an hour daily, but the number increases to 70 percent for 15-year-olds. And over the age of 15 kids become even less active.

Li found that, after high school, physical activity levels got even lower. Those who did attend college were slightly more active than those who didn’t, and of the college students, those living outside schools exercised less than on-campus students.

Kids who don’t get enough exercise often face serious health problems later in life. Li had a different set of recommendations for college students and those who don’t attend college.

“Colleges should ask students to do more physical activities -not just to build more centers, but to encourage students with more programs,” said Li.

For those who don’t attend college, Li believes that “government and communities” should know their needs and do more.

Part of the reason kids are not getting enough exercise may be because of the fact that only 29 percent of U.S. high schools have daily gym classes.

【小题1】What do we know about Li’s research?

A．It was developed from surveys.

B．It asked students to exercise every day.

C．It got data with the help of accelerometers.

D．It didn’t agree with CDC’s recommendations.

【小题2】What do Li’s research findings and those of earlier studies have in common?

A．Kids exercise less and less as they get older.

B．Kids around 15 are the most active in exercising.

C．Kids without enough exercise face more health problems.

D．Kids who attend college practice more than those who don’t.

【小题3】What measure should colleges take?

A．Working with the local government and communities.

B．Giving students more chances for physical activity.

C．Preventing students from living outside schools.

D．Increasing the number of gyms in the colleges.

【小题4】What’s the main idea of this text?

A．Pushing college students to get exercise is not easy.

B．CDC suggests that teens should exercise every day.

C．Teens who exercise daily often live a healthy life.

D．90% of U S. teens aren’t getting enough exercise.