Câu hỏi: This is the instance where big, obvious non-verbal signals are appropriate.

A. situation

B. attention

C. place

D. matter

Câu 1: Some of the participating schools have also decided to use green cleaning products, which are safer since they do not ……. harmful chemicals into the environment.

A. release

B. expose

C. compound

D. deplete

Câu 2: Deserts often include _________ and rocky surface.

A. oil

B. water

C. sand

D. trees

Câu 3: ______- is natural environment in which plant or animals live.

A. Ecology

B. Habitat

C. Extinction

D. Biodiversity

Câu 4: Billy, come and give me a hand with cooking.

A. help

B. prepared

C. be busy

D. attempt

Câu 5: The construction work was carried out by the local contractor.

A. continued

B. completed

C. done

D. run

Câu 6: When you see your teacher approaching you, a slight wave to attract his attention is appropriate.

A. coming nearer to

B. pointing at

C. looking up to

D. catching sight of