Câu hỏi: Names of people in the book were changed to preserve anonymity.

A. reveal

B. conserve

C. cover

D. presume

Câu 1: No one knew precisely what would happen to a human being in space

A. casually

B. flexibly

C. wrongly

D. informally

Câu 2: Synthetic products are made from chemicals or artificial substances.

A. natural

B. made by machine

C. man-made 

D. unusual

Câu 3: Affluent families find it easier to support their children financially.

A. Wealthy

B. Well-off 

C. Privileged

D. Impoverished

Câu 4: I take my hat off to all those people who worked hard to get the contract.

A. congratulate

B. unrespect

C. welcome

D. encourage

Câu 5: About 95% of all animals are invertebrates which can live anywhere, but most, like the dtarfish and crab, live in the ocean.

A. with backbones

B. with ribs

C. without ribs

D. without backbones

Câu 6: Slavery was abolished in the US in the 19th century.

A. instituted

B. eradicated 

C. eliminated

D. required