Câu hỏi: Choose the correct answer A, B, C or D.

A. less convenient as

B. less convenient than

C. not so convenient than

D. the most convenient as

Câu 1: In 1850 ........................ established one of the first detective agencies in theUnited States.

A. it was detectivePinkerton

B. detective Pinkerton 

C. detective Pinkerton who

D. when detectivePinkerton

Câu 2: Samuel Clemens, ................ under the pen name Mark Twain, createdcharacters that reflected purely American life.

A. he wrote

B. was writing

C. wrote

D. who wrote

Câu 3: The electric light bulb ........................ by Thomas Edison.

A. invented

B. was invented

C. invents

D. is invented

Câu 4: Ansel Adams was a landscape photographer ............................. photographs show the nature of the western United States.

A. of his

B. whose 

C. of whom

D. his

Câu 5: Commercial centers are ................ they were many years ago.

A. as popular than

B. the most popular

C. the most popular than

D. more popular than

Câu 6: Choose the correct answer to fill in the blank. 

A. that are

B. being

C. are

D. are being