The passage is mainly about ______.A．the u

问题单项选择题

The passage is mainly about ______.

A．the uses of life preservers

B．the design of life preservers

C．the materials for life preservers

D．the buoyancy of life preservers

答案

参考答案：B

解析：[试题分析] 文章主旨题。
[详细解答] C项和D项都是对救生衣设计中设计材料的说明。A项为陷阱，指救生衣的用途，尽管开头提到，但范围不着边际。故只有B是正确选项。