Câu hỏi: I_______ George on my way home.

A. dropped in on

B. gear up for

C. pair up with

D. look back on

Câu 1: He formerly worked as a machinist_______ in Boeing's Everett assembly plant.

A. appriciate

B. apprentice

C. appraise

D. approach

Câu 2: I’m trying to_______ the amount of sugar I eat.

A. cut down on

B. bear out

C. bring in

D. team up with

Câu 3: Some______ animals become tame if they get used to people.

A. wild

B. domestic

C. endangered

D. rare

Câu 4: He had a new heart valve _______.

A. added

B. supplanted

C. improved

D. implanted

Câu 5: We all regard pollution as a.......... matter to human beings.

A. solemn 

B. great

C. serious 

D. huge

Câu 6: Installing is firewall is one method of trying to protect against_______.

A. hackers

B. thiefs

C. robbers

D. crooks