问题补充:
The serious expression of the captain kept his crew .
A. in the distance
B. from a distance
C. in a distance
D. at a distance
答案:
A. in the distance
B. from a distance
C. in a distance
(答案→)D. at a distance
解析:考查词组:keep sb at a distance使…保持一段距离,句意:船长的严肃的表情使船员和他保持一定距离。in the distance在远处,from a distance从远处,C项是错误的词组,选D。