Câu hỏi: 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 1: Do you know how many countries __________ part in the sporting event?

A. take

B. make

C. have

D. do

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

A. happen

B. encounter

C. arrive 

D. clean

Câu 3: With the strong support of their countrymen, the Vietnamese athletes competed in ___________ spirits.

A. big

B. strong

C. high

D. lot

Câu 4: Many plants and animal species are now on the _______ of extinction.

A. danger

B. border

C. margin

D. verge

Câu 5: We must start a …………. for illiteracy eradication immediately

A. contest

B. company

C. champion

D. campaign

Câu 6: This is the instance where big, obvious non-verbal signals are appropriate.

A. situation

B. attention

C. place

D. matter