Mark the letter A, B, C or D on your answer sheet to show the underlined part that needs correction in each of the following questions.
The doctor's records must be kept (A) thorough and (B) neatly (C) so as to insure (D) good book – keeping.

A.thorough

B.neatly

C.so as to

D.good

Trong các hợp chất, kim loại nhóm IIA có số oxi hóa là

A. +1.         

B. +3.         

C. +2.         

D. +4.