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: They don't seem particularly worried about the situation.

A. concerned

B. pleased

C. frightened

D. excited

Câu 2: The plants and animals of the sea fall into three major groups.

A. small

B. chief

C. minor

D. main

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

A. Wealthy

B. Well-off

C. Privileged

D. Poor

Câu 4: Fish only species that are not of concern, threatened or endangered.

A. educated

B. healed

C. defended

D. brought

Câu 5: Be quiet or you'll wake the whole house!

A. still

B. noisy

C. peaceful

D. tranquil

Câu 6: Advanced students need to be aware of the important of collocation.

A. of high level

B. of great important

C. of low level

D. of steady progress