Câu hỏi: 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 1: Exactly .............. we can replace our soil disappearing through erosion is not known.

A. what

B. how

C. if

D. because

Câu 2: Hamburgers ...................... favorite in America in the early century.

A. became

B. becomes

C. has become

D. was become

Câu 3: 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 4: What would you do if war .......................... ?

A. break out

B. will break out

C. were to break out

D. breaks out

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: We’ll have to break the ice on the pond; otherwise the ducks .............. swim.

A. are not able to

B. will not be able to

C. would not be able to

D. would not have been able to