Câu hỏi: ......................... 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

Câu 1: Exactly .............. we can replace our soil disappearing through erosion is not known.

A. what

B. how

C. if

D. because

Câu 2: The farmers got their crops ................... earlier than they hadexpected.

A. picked 

B. has picked

C. pick

D. was picked

Câu 3: 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 4: If it ..................... last weekend, we would have gone skiing.

A. snowed

B. would have snowed

C. had snowed

D. would snow

Câu 5: .............................. if I were you.

A. These wires would look dangerous

B. You should not touch these wires

C. I would not touch these wires

D. These wires were dangerous to you not to me

Câu 6: Their popularity ................ much more after the Second WorldWar.

A. grew

B. grow

C. is grown

D. has grown