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: Paul and Linda .............. us to their party last weekend.

A. was inviting

B. invited

C. had been inviting

D. will invite

Câu 2: My parents    ........... in Florida since 1999.

A. has lived

B. have lived

C. are living

D. live

Câu 3: Rita .................. class every day.

A. not to attend

B. doesn’t attend

C. not attending

D. isn’t attended

Câu 4: We always...................... a present to Elsa on her birthday.

A. are taking

B. taking

C. take

D. are taken

Câu 5: 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 6: I .............. Michael for years.

A. have known

B. know

C. knowing

D. was known