Câu hỏi: For thousands of years, man has created sweet-smelling substances from wood, herbs and flowers and using them for perfumes or medicine.

A. man

B. sweet-smelling

C. using them

D. or

Câu 1: Not everyone realizes that the most largest organ of the human body is the skin.

A. not everyone

B. most largest

C. human

D. is

Câu 2: I clearly remember to tell you about this before.

A. clearly

B. remember

C. to tell 

D. about

Câu 3: I was very busy lately since the project of designing the new collection started.

A. was

B. since

C. the project

D. the new collection

Câu 4: Little he knows about the surprise that awaited him.

A. he knows

B. about

C. the

D. awaited

Câu 5: By measuring the color of a star, astronomers can tell how hot is it.

A. measuring

B. the

C. how

D. is it

Câu 6: Unlike the old one, this new copier can perform their functions in half the time.

A. unlike

B. can perform

C. their functions

D. in half the time