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

A. snowed

B. would have snowed

C. had snowed

D. would snow

Câu 3: Hamburgers ...................... favorite in America in the early century.

A. became

B. becomes

C. has become

D. was become

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

A. if

B. in case

C. whether

D. provided

Câu 5: The first hamburgers ..................... in Connecticut in 1895.

A. are sold 

B. were sold

C. sold

D. have been sold

Câu 6: The hurricane was so strong that it damaged the whole area ........................ itwas approaching or receding.

A. whether

B. and if

C. but

D. because