His uncle will come about an hour.A. forB. atC. onD. in

问题补充：

His uncle will come about an hour.

A. for

B. at

C. on

D. in

答案：

A. for

B. at

C. on

(答案→)D. in

解析：本题是将来时，在将来时表示多久以后，通常用介词in，本题的含义是一个小时之后，他的叔叔将会过来，故选D。