He may not even drink water at night, swallowing insects possibly floating on the surface．
A. in case of
B. for fear of
C. for the sake of
D. in line with
网友回答
A. in case of
B. for fear of
C. for the sake of
D. in line with
解析：考查介词短语。In case of 以防，以免；for fear of 为了避免，害怕；for the sake of 为了；in line with 跟……一致，符合。