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

A. measuring

B. the

C. how

D. is it

Câu 1: It is time the government do something to help the unemployed to find some jobs.

A. do

B. time

C. the unemployed

D. some

Câu 2: Manufacturers may use food additives for preserving, to color, or to flavor, or to fortify foods.

A. may use

B. for preserving

C. to flavor

D. to fortify

Câu 3: 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 4: Sometimes it takes me about three hours finishing my round.

A. sometimes

B. me

C. hours

D. finishing

Câu 5: The Great Pyramid of Giza is said to have built over a 20-year period.

A. of

B. said

C. have built

D. a

Câu 6: Building thousands of years ago, the ancient palace is popular with modern tourists.

A. building

B. ago

C. the ancient 

D. popular with