Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is closest in meaning to each of the following questions.

The secret to success is hard work

A. One must work hard to keep secrets

B. Working hard ensures success

C. One cannot succeed if he has secrets

D. If you keep your work secret, you will succeed

Cho các chất: FeO,  FeCO 3 ,  Fe 2 O 3 ,  Fe ( NO 3 )   2 , Fe ( OH ) 2 ,  Fe ( OH ) 3 . Số chất bị dung dịch  HNO 3  loãng oxi hóa là

A. 4.

B. 1.

C. 3.

D. 2.