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

A. is

B. safeguarding

C. preservation

D. nature

Câu 1: It has ever been told that teaching is one of the more noble careers.

A. has ever been

B. is

C. the 

D. more noble

Câu 2: When a patient's blood pressure is much higher than it should be, a doctor usually insists that he will not smoke.

A. much

B. than it

C. should be

D. will not

Câu 3: Has the government made a decide to ban the use of chemical weapon yet?

A. has

B. decide

C. to ban

D. use

Câu 4: The master of ceremonies announced in a loud and clear voice and told that the dinner would be late due to unforseen circumstances.

A. of ceremonies

B. and told

C. would be

D. due to

Câu 5: Spell correctly is easy with the aid of a number of word processing programs for personal computers.

A. Spell

B. correctly

C. word processing

D. computers

Câu 6: The mother asked her son if he would have the floor clean the day before.

A. asked

B. if

C. would have

D. clean