—What about the protection?
—Let’s keep the surface dirt 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…free from使什么免受什么，句意：让我们使表面免受灰尘通过在上面放上一个盖。所以选B。