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

A. what

B. how

C. if

D. because

Câu 1: 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 2: A small design fault ................. on our latest chip.

A. has found

B. found

C. has been found 

D. find

Câu 3: Applicants ................ send in their CVs.

A. asked

B. ask to 

C. are asked to

D. asked to

Câu 4: Take John's address with you, ................... you have time to see him whenyou’re in London.

A. if

B. unless

C. in case

D. so long as

Câu 5: 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

Câu 6: .................................. , 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