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: Annette spent a year long to search for scholarship; ................, she did not get positive result.

A. therefore

B. moreover

C. still

D. asa result

Câu 2: I ................. the house before you called.

A. leave

B. am leaving

C. had left

D. had been leaving

Câu 3: The telephone .............. ten times before Patsy finally answered it.

A. rings

B. ringing

C. had rung

D. is ringing

Câu 4: Barbara .................. that package to you tomorrow morning.

A. deliver

B. is going to deliver

C. are going to deliver

D. delivering

Câu 5: Louise was listening to the radio while she .................. the house.

A. is cleaning

B. was cleaning

C. had cleaned

D. will dean

Câu 6: My parents    ........... in Florida since 1999.

A. has lived

B. have lived

C. are living

D. live