Khi nói về muối amoni, phát biểu không đúng là 

A. Muối amoni dễ tan trong nước

B. Muối amoni là chất điện li mạnh

C. Muối amoni kém bền với nhiệt

D. Dung dịch muối amoni có tính chất bazơ

Cho các este sau: etyl axetat, triolein, anlyl axetat, benzyl axetat, phenyl fomat, tristearin, isoamyl axetat, vinyl axetat. Cho các este tác dụng với dung dịch NaH (dư), đun nóng thu được số  ancol là.

A. 6

B. 5

C. 4

D. 3

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

Their big day requires (A) a lot of preparation, (B) such as designing costumes,(C)  choose (D)guests and  reinforcing security.

A. requires

B. preparation

C. costumes

D. shoose

Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that best combines each pair of sentences in the following questions.

The student was very bright. He could solve all the math problems

A. He was such bright student that he could solve all the math problems.

B. The student was very bright that he could solve all the math problems.

C. He was so bright a student that he could solve all the math problems.

D. Such bright was the student that he could solve all the math problems.

Mark the letter (A, B, C or D) on your answer sheet to indicate the word or phrase that is OPPOSITE in meaning to the underlined part in each of the sentences from 24 to 25

It's not polite to ask Americans questions about their age, marriage or income

A. unfriendly

B. discourteous

C. unacceptable

D. nice

Mark the letter A, B, C or D on your answer sheet to indicate the underlinedpart that needs correction in each of the following questions from 21 to 23.

Air pollution, together with littering, have been causing many problems in our large, industrial cities in the last few years

A. with

B. in our large

C. many

D. have been