问题补充:
Only when the war was over return home.
A. he was able to
B. was he able to
C. could he be able to
D. would he be able
答案:
A. he was able to
(答案→)B. was he able to
C. could he be able to
D. would he be able
解析:考查倒装结构。本题考查Only + 状语从句 + 主谓倒装结构,be able to用其过去式,表示成功的做某事,故选B。