Câu hỏi: 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 1: The developing of the submarine was hindered by the lack of a power source that could propel an underwater vessel.

A. developing

B. the

C. a power

D. could propel

Câu 2: 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 3: Each of the nurses report to the operating room when his or her name is called.

A. of the

B. report

C. his or her name

D. is called

Câu 4: The sates school system in England can be divided into two levels of educated: primary and secondary

A. be divided

B. into

C. educated

D. secondary

Câu 5: 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 6: The eastern bluebird is considered the most attractive bird native of North America by many bird-watchers.

A. bluebird

B. considered

C. native of

D. by