You will stay healthy ________ you do more exercises, such as running and walking.

A. if

B. how

C. before

D. where

?Is Tom at school today?

?No. He's at home ________ he has a bad cold.

A. because

B. if

C. until

D. before

This is the man ________ last night.

A. whom I saw him

B. whom I saw

C. which I saw

D. who I saw him

I asked ________.

A. whose watch is this

B. whose watch this is

C. whose was this watch

D. whose watch this was

I'll come to see you ________ I'm free next Sunday.

A. until

B. after

C. if

D. before

The picture ________ has a house and flowers is the one I like best.

A. who

B. which

C. where

D. whose

Do you know ________ the population of Shenyang?

A. what is

B. how much is

C. what are

D. how many are

He hasn't decide ________.

A. if he'll go on a trip to Hainan

B. when will he go on a trip to Hainan

C. if he goes on a trip to Hainan

D. when does he go on a trip to Hainan

Time passed quickly and three months went by ________ we knew it.

A. when

B. after

C. before

D. till

I don't know when ________. When he ________, I'll let you know.

A. will he come; will come

B. he will come; comes

C. he comes; will come

D. does he come; comes