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: Not one in one hundred children exposed to the disease are likely to develop symptoms of it.

A. not one

B. are

C. symptoms

D. it

Câu 2: Doctors believe there is better in this modern world of ours to try to prevent illnesses than to rely on medicines to cure them.

A. doctors

B. there is

C. of ours

D. to

Câu 3: We had better to review this lesson carefully because we will have some questions on it.

A. to review

B. carefully

C. will have

D. on

Câu 4: Parks which are found in downtown areas where office workers and store employees can enjoy their lunch hours sitting on the green grass in clean, fresh air.

A. which

B. employees

C. lunch hours sitting

D. fresh air

Câu 5: 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

Câu 6: The Red Cross organizes and leads relief assistance missions after natural disasters such as floods, tsunamis, earthquakes, and homelessness.

A. The Red Cross

B. organizes and leads

C. assistance missions

D. and homelessness