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。

5.If students follow the doctor’s suggestions they ______.

　A.may lighten their backpacks　 learn how to help themselves

　C.may feel their backpacks are lighter　D.will know how to wear backpacks

Passage 1

　[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。

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

3.The expression “switched to” in the text perhaps means ______.

　A. started to use B. turned to C. caught up D. used for

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

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

5.C.文章的最后一句话是解答本题的关键。

4.B.短文末段的首句已交代的非常清楚。

3.D.本题同样也是细节理解题。答案就在第二段的末句中。

2.B.本题属细节理解题。“Three months before he was born, his father ,William Blats, died.”是答案的出处。