Câu hỏi: 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 1: 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 2: Mary and her sister just bought two new winters coats at the clearance sale.

A. her sister

B. just bought

C. two new

D. winters

Câu 3: 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 4: 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

Câu 5: 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 6: 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