Câu hỏi: Exactly .............. we can replace our soil disappearing through erosion is not known.

A. what

B. how

C. if

D. because

Câu 1: What would you do if war .......................... ?

A. break out

B. will break out

C. were to break out

D. breaks out

Câu 2: If you'd told me you were coming, .............................

A. I can get some food in

B. I’d have found us something to eat

C. I made a lovely dish

D. I’ll buy some more food

Câu 3: If it ..................... last weekend, we would have gone skiing.

A. snowed

B. would have snowed

C. had snowed

D. would snow

Câu 4: If they offered you the job, .................................... ?

A. will you accept it

B. have you accepted it

C. would you have accepted it

D. do you think you would accept it

Câu 5: If I’d known you weren’t coming, ................................

A. I had come too

B. I would like to know why

C. I wouldn’t have gone to so much trouble

D. I hadn’t been so upset

Câu 6: ......................... any difficulty operating the machine, do not hesitate totelephone our service department.

A. Should you have

B. If you should

C. In case you have

D. Unless you have