问题补充:
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
答案:
A. 1950’s; twenties
(答案→)B. the 1950s; his twenties
C. 1950’s; the twenties
D. 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。