Are you carrying too much on your back at school? You’re not alone. Back experts in the United States are worried that young students are having back and neck problems as a result of carrying too much in their backpacks (schoolbags).
　　“It hurts my back when I run,” said Oberlin Reyes, a student in Virginia. “It’s hard to get up the stairs with my backpack, because it’s too heavy.”
　　Oberlin is among students whose backpacks were weighed for a week in a recent study.
　　They had regular backpacks with two straps (带子) to carry them, but a number of students with heavy loads had switched to rolling backpacks (which have wheels and can roll on the ground).
　　Shirley Park, whose backpack weighed 10 kilograms, said she changed to a rolling backpack because she was starting to have back pain.
　　How much is too much? Experts say students should carry no more than 10 to 15 percent of their own body weight.
　　A few students had one suggestion to lighten the load: less homework.
　　P.S. (附) Doctor’s suggestion:
　　① Lighten the load. Clean out binders (活页材料) and take home only the books you need that night.
　　② Wide straps are better. They send out the weight over your shoulders more evenly (均匀). And be sure to wear both straps rather than hanging the pack over one shoulder.
　　③ Pack smart. The heavier things should be packed closed to the back.
　　④ Bend both knees when you pick up the pack, and don’t just bend over at the waist (腰).

　　1.“_____” is the main idea of the text.
　　A.The problem of backpacks is worth studying　B.The problem made by heavy backpacks
　　C.What is the best backpack for a student　D.How to make students’ backpacks light

　　2.According to Enderlin Reyes and Shirley Park, we know ______.
　　A.students have to do too much homework　
　　B.backpacks have to carry heavy backpacks
　　C.backpacks without wheels are bad for students
　　D.too much homework leaves students no free time

　　3.The expression “switched to” in the text perhaps means ______.
　　A. started to use B. turned to C. caught up D. used for

　　4.According to the passage, it’s better for a student of 40 kilograms to carry a backpack of _____ at most by the words of experts.
　　A. 10 kg B. 8 kg C. 6 kg D. 7 kg

　　5.If students follow the doctor’s suggestions they ______.
　　A.may lighten their backpacks　B.can learn how to help themselves
　　C.may feel their backpacks are lighter　D.will know how to wear backpacks

　　【答案与解析】

　　这篇短文反映了学生书包过重这一引发人们思考的生活现实。书包过重引起了学生身体的不适。文中引用了几位学生对沉重书包的感想和体会，有的学生甚至还在书包上安装了轮子。专家认为书包重量不应超过学生体重的10%-15%。学生则认为减少作业量才能彻底解决这一问题。为了减小过重书包对学生身体造成的伤害，短文最后还附了医生的四点建议。
　　1.D 根据首段末句及所附医生的建议可知选项D乃是文章主旨。
　　2.A 短文前两句是本题答案之所在。
　　3.A 根据该词组所在句子及上下文意思，“许多学生使用带有轮子，可在地上滚动的书包”可以推测选项A的解释合乎文意。
　　4.C 专家建议学生书包重量应在他本人体重的10% 和15%之间。所以一个体重为40千克的学生所背书包的重量应是6千克。
　　5.C 显然，专家所提四项建议的目的是让学生的书包轻一些。