Question

His grandfather wrote a lot of instructive stories for children,_____this is one example求大神指教

1.His grandfather wrote a lot of instructive stories for children,_____this is one example.
A in which B of which C by which D of which

2.Dd you know the gentleman _____ our president is shaking hands ______. A with whom , 不填B.whom,byC.that,不填D.for whom,with

3.He offerd us a lot of money ______we couldnt have introduced the advanced machines from abroad.
A. without which B.with that C.with which D.without that

求详细解答以上三题，定语从句到底怎么做？？？急需帮助啊！！！
还有这个题
The professer mentioned some poets and poems ________ were unknown to us in his lecture.
A. which B. who C.that D.whom 为什么选that不选which？？？
I ‘m sorry but I wont have time to be with you until after 5:30 PM,_____I will have done all my work.
A.whose time B.at which timeC.on which D.by which time

Answer 1

1.B of which 这是其中的一个例子。同类当中的一个所以是of
2. A shake hands with sb 和某人握手。
在这里把介词提前了，是介词+关系代词的形式。
3. A 后边从句的意思是我们就不会从国外引进先进的机器。所以是没有这些钱的话。
C最后一个题中，先行词是some poets and poems，诗歌和诗人，既有人又有物，这个时候关系词只能用that 。

追问

那第三题为什么不能选D without that 呢，是不是因为without是介词，后边不能加that啊

追答

对的，如果是介词+关系代词的形式，这个时候是不能用that 的。
D by 可以表示到……为止。所以是到下午五点半的时候我就已经完成我的工作了。

追问

最后一个问题I ‘m sorry but I wont have time to be with you until after 5:30 PM,_____I will have done all my work.
A.whose time B.at which timeC.on which D.by which time
为什么选B

追答

我觉得应该选择D 。从句子的时态 I will have done all my work.可以确定。
by 可以表示到……为止。所以是到下午五点半的时候我就已经完成我的工作了