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: The store ..................... two sales so far this year.

A. is having

B. has been having

C. has

D. has had

Câu 2: Television is a prime source of home entertainment; ................, it is a cheap babysitter.

A. furthermore

B. therefore

C. accordingly

D. on the contrary

Câu 3: Barbara .................. that package to you tomorrow morning.

A. deliver

B. is going to deliver

C. are going to deliver

D. delivering

Câu 4: 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 5: Before the police arrived, the robbers ..........................

A. run

B. had run

C. have run

D. have been running

Câu 6: Mr. and Mrs. Wilson .............. some disputes with their neighbors.

A. having

B. have been having

C. have having

D. have been had