Câu hỏi: The old drainage pipelines must be maintained; ................, leakage will be unavoidable.

A. therefore

B. similarly 

C. on the contrary

D. otherwise

Câu 1: I ............... on the bus when I dropped my wallet.

A. am getting

B. get

C. have gotten

D. was getting

Câu 2: We .............. to the baseball game when it started to rain.

A. are driving

B. drives

C. driven

D. were driving

Câu 3: We always...................... a present to Elsa on her birthday.

A. are taking

B. taking

C. take

D. are taken

Câu 4: My parents    ........... in Florida since 1999.

A. has lived

B. have lived

C. are living

D. live

Câu 5: Some people are using motorbikes for transportation; ....................., others are taking publicvehicles to get to their destination.

A. hence

B. otherwise

C. therefore

D. besides

Câu 6: Many ads do give important information about products; ....................., some of them are merelyhumorous or foolish.

A. furthermore

B. however

C. consequently

D. at the same time