Câu hỏi: At times, this can be risky, and the keepers have been injured and one has been killed.

A. good

B. useful

C. healthy

D. secure

Câu 1: Keep only fish that you will eat; release the rest.

A. catch

B. hold

C. take

D. have

Câu 2: Use water sparingly and keep water clean.

A. dusty

B. dirty

C. wicked

D. halfway

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

A. uncomfortable

B. dirty

C. lazy

D. warm

Câu 4: One in seven accidents is caused by sleepy drivers.

A. awake

B. unwell

C. exhausted

D. talkative

Câu 5: Last night they stayed at home and watched TV.

A. day

B. noon

C. midnight

D. morning

Câu 6: We know not what is good until we have lost it.

A. find

B. count

C. guess

D. learn