Câu hỏi: It is difficult to write rules that tell exactly when we should apologize, and it is not difficult to learn how to do it.

A. difficult

B. that

C. when

D. and

Câu 1: A beaver uses its strong front_teeth to cut down trees and peel_off its bark.

A. its

B. front teeth

C. eel off

D. its

Câu 2: The notion that students are not sufficiently involved in their education is one reason for the recently surge of support for undergraduate research.

A. notion

B. are not

C. their education

D. recently

Câu 3: These snakes will not cause you any serious harm. They are harmful.

A. snakes

B. cause

C. harm

D. harmful

Câu 4: The office manager insists that his staff use all of their vacation time, but he hardly never takes a vacation himself.

A. insists

B. use

C. their

D. hardly never

Câu 5: More Asian students than American counterparts agree that a husband is obliged tell his wife where he has been if he comes home late.

A. than

B. counterparts

C. tell

D. has been

Câu 6: The Commitments of Traders Report is released by the Commodity Futures Trading Commission on eleventh day of each month.

A. released by

B. on eleventh

C. of

D. month