Câu hỏi: A chronic lack of sleep may make us irritable and reduces our motivation to work.

A. uncomfortable

B. responsive

C. calm

D. miserable

Câu 1: In some countries, the disease burden could be prevented through environmental improvements.

A. something to stiffer

B. something enjoyable

C. something sad

D. something to entertain

Câu 2: My cousin tends to look on the bright side in any circumstance.

A. be optimistic

B. be pessimistic

C. be confident

D. be smart

Câu 3: Solar energy is not only plentiful but also infinite.

A. without limit

B. boundless

C. limited

D. indefinite

Câu 4: There has been no discernible improvement in the noise levels since lorries were banned.

A. insignificant

B. clear

C. obvious

D. thin

Câu 5: The only means of access to the station is through a dark subway.

A. arrival

B. admission

C. outlet

D. output

Câu 6: We'd better speed up if we want to get there in time.

A. slow down

B. turn down

C. put down

D. lie down