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 do decide to come, ............................

A. the party’s always a success

B. we would have been so happy

C. I won’t be coming either

D. let me know

Câu 2: If only you’d come, ...............................

A. I’ll be the happiest girl alive 

B. I’ll understand why

C. I’d have had a lovely time        

D. I would look forward to it

Câu 3: .................................. , the phone will be cut off.

A. If you paid the phone bill today

B. Unless you pay the phone bill today

C. On condition that you had paid the phone bill before

D. In case you have paid the phone bill

Câu 4: Hamburgers ...................... favorite in America in the early century.

A. became

B. becomes

C. has become

D. was become

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

A. chose

B. was chosen 

C. choose 

D. have been chosen