Mark the letter A, B, C or B on your answer sheet to indicate the underlined part that needs correction in each of the following questions.

He (A) comes from a (B) large family, all of (C) them now (D) live in Australia.

A. comes 

B. large family

C. them 

D. live in 

Tìm hệ số của  x 7 trong khai triển  P ( x ) = ( x + 1 ) 20

A.  C 20 7

B.  A 20 7

C.  A 20 13

D.  P 7