（介词+关系代词）
in(over,about,through,with,for)which (whom).etc.
1.The dictionary ___ ___ so many pages are missing is useless.
2.This is the boy ___ ___ we have to say "Thank you".
3.I have not met Mr Wang ,the son ___ ___ is my English teacher.
4.The old couple ___ ___ I lived in Abington were very nice to me.
5.That was the period ___ ___my cousin stayed in my home.
6.The building ___ ___ we held the meeting last year has been pulled down.
7.We are reading a book ___ ___ there are a lot of mistakes.
8.John,___ ___ we talked yesterday,is from Canada.
9.The big fire,___ ___ about 40 people died,lasted about 4 hours.
10.Lu Xun has written many famous stories,___ ___ this is only one example.