---Yourgrandfatherstillseemsveryenergetic,althoughheisa...

问题详情：

---Your grandfather still seems very energetic, although he is already in his seventies now.

---Yes, he _______in the army for three years when he was young.

A． would serve             B． served

C． had served               D． has served

【回答】

B

知识点：动词时态与语态

题型：选择题