The sun heats the earth,（）is very important to living things.

单项选择题This is the problem（）we have no good solution as yet.

A.to that
B.which
C.for which
D.to which

单项选择题Last month, he paid a visit to the village（）he had once worked for five years.

A.where
B.which
C.that
D.in that

单项选择题Mr. Liu,（）at university in Changchun, works at Changhou Company now.

A.whose wife I met
B.I met whose wife
C.I met his wife
D.his wife I met

单项选择题Let's go to the cinema,（）?

A.will you shan‘t we
B.shan‘t we
C.don‘t we
D.shall we

单项选择题He seldom does his homework at school on weekdays,（）he?

A.doesn‘t
B.isn‘t
C.does
D.is

单项选择题You like playing football，（）you？

A.do
B.didn‘t
C.did
D.don‘t

单项选择题There wasn't any paper in the box,（）?

A.wasn‘t there
B.was there
C.wasn‘t any
D.was any

单项选择题I don't think he will be back in an hour,（）?

A.doI
B.won‘t he
C.don‘t I
D.will he

单项选择题Somebody asked her,（）

A.did he
B.didn‘t they
C.didn‘t he
D.did they

单项选择题Silk（）by Chinese for thousands of years now.

A.has used
B.has been used
C.was used
D.is used