Mark the letter A, B, C or D on your answer sheet to indicate the underlined part following that needs correcting.
The World Health Organization’s main activities (A) are carrying of (B) research on (C) medical development and improving (D) international health care
A. main activities
B. carrying of
C. on
D. improving
Chọn B
Carrying out research = tiến hành cuộc nghiên cứu. Sửa “of” thành “out”