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: 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 2: 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

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

A. without limit

B. boundless

C. limited

D. indefinite

Câu 4: His replies were inconsistent with his previous testimony.

A. contradicted

B. compatible

C. enhanced

D. incorporated

Câu 5: She wrote me a vicious letter.

A. helpful

B. gently

C. dangerous

D. healthy

Câu 6: It was apparent from her face that she was really upset.

A. obvious

B. indistinct

C. transparent

D. evident