after having two periods of a challenge为什么用不定冠词

after having two periods of achallenge
请先 登录 后评论

1 个回答

after having two periods of a challenge=在经历两个阶段/时期的(相同)挑战之后?备注:以上不定冠词a相当于the same.类似于They are of an age.=They are of the same age.
请先 登录 后评论