Câu hỏi: 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 1: There was a gradual raise in the number of literate males and females in the lowlands.

A. a gradual

B. raise

C. literate

D. the lowlands

Câu 2: 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 3: 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 4: The guide told the tourists that it was a good restaurant specializing in seafood just round the corner from the museum.

A. The

B. it was a

C. specializing

D. just round

Câu 5: 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 6: 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