Crom có số oxi hóa +2 trong hợp chất nào sau đây 

A. CrSO 4  

B. K 2 Cr 2 O 7  

C.  Cr 2 O 3  

D. NaCrO 2

Mark the letter A,B, C or D on your answer sheet to indicate the most suitable response to complete each of the following exchanges

“ I like your coat, Helen.”        -“_______.”

A.Really, I’m not.

B. Do you?

C. I think so

D. I’m sorry.