1.Ancient China was a place where states were often at war with each other.
2.October 1,1949 was the day when the People's Republic of China was founded.
3.I don't know the reason why she looks unhappy today.
4.The man who is shaking hands with my father is a policeman.
5.This is the scientist whose name is known all over the country.
6.Guilin is a city which/that has a history of 2,000 years.
7.That is all that I want to say.
8.We jumped with joy at the news, which was natural.
9.I hope to get such a dictionary as he is using.
10.He gave his mother a colour TV set for her birthday, which pleased her a lot.
11.This is the teacher from whom we've learnt a lot.