My father served in the army in when he was in .
A. 1950s; twenties
B. the 1950s; his twenties
C. the 1950s; the twenties
D. 1950s; the twenties
网友回答
A. 1950s; twenties
(答案→)B. the 1950s; his twenties
C. the 1950s; the twenties
D. 1950s; the twenties
解析：考查短语。in the 1950s 在20世纪50年代，这是固定的表达。In one’s twenties 在某人20多岁的时候。选B。