Câu hỏi: We cannot clean up our polluted rivers and seas overnight.

A. cleared

B. purified

C. honored

D. respected

Câu 1: Rapid run-off would cause frequent floods and leave little water during fry seasons.

A. Bad

B. Weak

C. Slow

D. Ugly

Câu 2: Fruit and vegetables grew in abundance on the island. The islanders even exported the surplus.

A. large quantity

B. small quantity

C. excess

D. sufficiency

Câu 3: She had a cozy little apartment in Boston.

A. uncomfortable

B. warm

C. lazy

D. dirty

Câu 4: Toxic chemicals continue to be dumped in the North Sea.

A. stop

B. go on

C. follow

D. begin

Câu 5: When did Nguyen Hue defeat Thanh enemies?

A. peoples

B. animals 

C. friends

D. kids

Câu 6: Visitors, especially children, can go there to learn how to recognize the different species of animals and plants.

A. pure

B. same

C. alike

D. whole