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: Many languages used around the world they do not have a form of writing.

A. used

B. around

C. they

D. a form of writing

Câu 2: Sometimes it takes me about three hours finishing my round.

A. sometimes

B. me

C. hours

D. finishing

Câu 3: I clearly remember to tell you about this before.

A. clearly

B. remember

C. to tell 

D. about

Câu 4: It is the recommendation of many psychologists that a learner ought to use mental images to associate word and remember them.

A. recommendation

B. ought to use

C. to associate word

D. remember them

Câu 5: John announced that he could not longer tolerate the conditions of the contract under which he was working.

A. announced that

B. not longer tolerate

C. of

D. under which

Câu 6: 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