Câu hỏi: It is easy to open a shop but hard to keep it always open.

A. welcome

B. appear

C. switch

D. close

Câu 1: Fish only species that are not of concern, threatened or endangered.

A. educated

B. healed

C. defended

D. brought

Câu 2: 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

Câu 3: He had never experienced such rudeness towards the president as it occurred at the annual meeting in May.

A. thought

B. hostility

C. care

D. politeness

Câu 4: The plants and animals of the sea fall into three major groups.

A. small

B. chief

C. minor

D. main

Câu 5: 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 6: Be quiet or you'll wake the whole house!

A. still

B. noisy

C. peaceful

D. tranquil