--What about the protection?
---Let’s keep the surface dirty by putting a cover over it.
A. far from
B. free from
C. apart from
D. away from
网友回答
A. far from
(答案→)B. free from
C. apart from
D. away from
解析：考查短语：keep sth free from 使某物免受什么，句意：这个保护怎么样？让我们使表面免受脏东西通过在上面放一个盖子。所以选B。