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: Be careful about the time. If you .................. too long on the first question,you ............... enough time to do the others properly.

A. had spent - would not have

B. had spent – would not have had

C. spend - will not have

D. spent - would not have had

Câu 2: If you’re not coming, ............................

A. we had not been in such trouble

B. you may need to tell me

C. we’d never met

D. you’d be so lucky

Câu 3: The hurricane was so strong that it damaged the whole area ........................ itwas approaching or receding.

A. whether

B. and if

C. but

D. because

Câu 4: Send my regards to Lawrence ............................ you see him.

A. if

B. in case

C. whether

D. provided

Câu 5: Exactly .............. we can replace our soil disappearing through erosion is not known.

A. what

B. how

C. if

D. because

Câu 6: If it ............................... his wife’s money, he’d never be a director.

A. was

B. isn’t 

C. had had

D. were not for