Câu hỏi: 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

Câu 1: Many plants and animal species are now on the _______ of extinction.

A. danger

B. border

C. margin

D. verge

Câu 2: 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 3: Whenever problems come up, we discuss them frankly and find solutions quickly.

A. happen

B. encounter

C. arrive 

D. clean

Câu 4: Although the staff did expand somewhat for the first century of its existence, the entire teaching staff consisted of the president and three or four tutors.

A. to and from

B. more or less

C. back and forth

D. side by side

Câu 5: This is the instance where big, obvious non-verbal signals are appropriate.

A. situation

B. attention

C. place

D. matter

Câu 6: The SEA GAMES is a ____________ multi-sport event involving participants from the current 11 countries of Southeast Asia.

A. annual

B. biennial

C. triennial

D. quadrennial