Câu hỏi: Please tell us the reason when he left without saying goodbye.

A. tell

B. when

C. left

D. saying

Câu 1: The puppy stood up slowly, wagged its tail, blinking its eyes, and barked.

A. slowly

B. its

C. blinking

D. and

Câu 2: Before went abroad, he had finished his English course at the English-speaking Center.

A. went

B. abroad

C. had finished

D. English-speaking

Câu 3: Conservation is the safeguarding and preservation of nature resources.

A. is

B. safeguarding

C. preservation

D. nature

Câu 4: This apprentice has spent two weeks to work on that new machine.

A. has spent

B. to work

C. on

D. new machine

Câu 5: What happened in New York were a reaction from city workers, including firemen and policemen who had been laid off from their jobs.

A. What happened

B. were

C. including

D. their

Câu 6: The deadbolt is the best lock for entry doors because it is not only inexpensive but installation is easy.

A. the best

B. because

C. not only

D. installation is easy