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

A. what

B. how

C. if

D. because

Câu 1: A new chairman ................. by our staff.

A. chose

B. was chosen 

C. choose 

D. have been chosen

Câu 2: ...................... we would have lost the match.

A. Unless the goal-keeper had played well

B. But for the goal-keeper’s heroics

C. If it were not for the goal-keeper

D. Because the goal-keeper was good

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: What would you do if war .......................... ?

A. break out

B. will break out

C. were to break out

D. breaks out

Câu 5: .................................. , 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 6: The first hamburgers ..................... in Connecticut in 1895.

A. are sold 

B. were sold

C. sold

D. have been sold