Câu hỏi: Jason’s professor had him to rewrite his thesis many times before allowing him to hand it in.

A. had

B. to rewrite

C. many times

D. allowing

Câu 1: 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 2: Conservation is the safeguarding and preservation of nature resources.

A. is

B. safeguarding

C. preservation

D. nature

Câu 3: 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

Câu 4: Unless there had been a heavy storm, the climbers will not have died.

A. Unless

B. had been

C. heavy

D. will

Câu 5: Has the government made a decide to ban the use of chemical weapon yet?

A. has

B. decide

C. to ban

D. use

Câu 6: Do most boys and girls give a great deal of thought to their future employ?

A. most

B. give

C. thought

D. employ