My father served in the army in when he was in .A. 1950’s; twentiesB. the 1950s; his twen

My father served in the army in when he was in .
A. 1950’s; twenties
B. the 1950s; his twenties
C. 1950’s; the twenties
D. 1950s; the twenties

A. 1950’s; twenties(答案→)B. the 1950s; his twentiesC. 1950’s; the twentiesD. 1950s; the twenties解析：考查数词。In the 1950s/1950’s在20世纪50年代；in one’s twenties在某人20多岁时。句意：我父亲参军是在20世纪50年代，那时他20多岁。

哦，回答的不错