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: If you ................... a pet bird, you’ll have to buy a cage, too.

A. buy

B. will buy

C. bought

D. had bought

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

A. what

B. how

C. if

D. because

Câu 4: A new chairman ................. by our staff.

A. chose

B. was chosen 

C. choose 

D. have been chosen

Câu 5: She has just had her book .......................

A. published

B. be published

C. publish

D. to publish

Câu 6: Peasants spend most of their time on the ground, ...................... many speciesstay in trees at night.

A. if

B. though

C. because

D. as well as