a.Is it hard to learn french b.Just thank of the hours of hard work--Billy has spent.
问题描述：
a.Is it hard to learn french b.Just thank of the hours of hard work--Billy has spent.
A.whenBwhichCon which D.in which请问一下理由及答案
答案为B
答
C,因为首先从句补充完整是Billy has spent the hours on hard work
词组spend on sth 或spend in doing sth 所以排除D
又因为此句是定语从句,从句里少了on hard work ,所以填on which,which指代hard work
所以不选B,又因为此句不涉及时间,所以不选A,选A时候例如：he doesn't know the day when Billy got married.