Chất nào sau đây vừa phản ứng được với dung dịch KOH, vừa phản ứng được với dung dịch HCl? A. C₆H₅NH₂

A. C₆H₅NH₂

B. H₂NCH(CH₃)COOH

C. C₂H₅OH

D. CH₃COOH

X, Y là hai hợp chất hữu cơ đơn chức. Nếu đốt cháy X, Y với số mol bằng nhau hoặc khối lượng bằng nhau thì đều thu được CO₂ có tỉ lệ mol tương ứng là 2 : 3 và hơi nước có tỉ lệ mol tương ứng là 1: 2. Hỗn hợp X, Y có phản ứng tráng bạc. Có bao nhiêu cặp chất X, Y thỏa mãn điều kiện trên ?

A. 3

B. 2

C. 1

D. 4

Cho axit cacboxylic X phản ứng với chất Y thu được một muối có công thức phân tử C₂H₇O₂N (sản phẩm duy nhất). Số cặp X và Y thỏa mãn điều kiện trên là

A. 2

B. 3

C. 4

D. 1

Mark the letter A, B, C or D on your answer sheet to indicate the word(s) CLOSET in meaning to the underlined word(s) in each of the following questions.

Tourists today flock to see the two falls that actually constitute Niagara falls.

A. come out of boredom

B. come in large numbers

C. come without knowing what they will see

D. come by plane

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 25 to 29. Fill in the appropriate word in question 28

  It can take a long time to become successful in your chosen field, however talented you are. One thing you have to be aware of is that you will face criticism along the way. The world is full of people who would rather say something negative than positive. If you’ve made up your (25) ______ to achieve a certain goal, such as writing a novel, don’t let the negative criticism of others prevent you from reaching your target, and let the constructive criticism have a positive effect on your work. If someone says you’re totally in the (26) _______ of talent, ignore them. That’s negative criticism. If, (27) ________, someone advises you to revise your work and gives you a good reason for doing so, you should consider their suggestions carefully. There are many film stars who were once out of work. There are many famous novelists who made a complete mess of their first novel – or who didn’t, but had to keep on approaching hundreds of publishers before they could get it (28) _______. Being successful does depend on luck, to a certain extent. But things are more likely to (29) _______ well if you persevere and stay positive.

A. to publish

B. published

C. publishes

D. publish

Đọc kĩ đoạn văn sau để trả lời các câu hỏi.

New York City is located in the southeastern part of New York States just east of New Jersey. The city was founded by the Dutch in 1624. At first, it was called Fort Amsterdam, and then New Amsterdam. In 1664, the English took over the city and renamed it New York. With the population of more than 7 million in the city and 19 million in the metropolitan region, New York is the largest city in the United States. It is divided into five parts, which are Manhattan, the Bronx, Brooklyn, Queens, and Staten Island. The total area of these parts is 964 square kilometers. Visitors to New York are all attracted by places such as the Statue of Liberty, the Empire State Building, Times Square, Wall Street, and Broadway theatre district. New York is also where tourists can visit some world famous art galleries and museums.

1. Where is New York City ?
2. Why was New York originally called New Amsterdam ?
3. When was it found ?
4. How many parts are there in the city ?
5. What are visitors to New York attracted by ?

Chọn đáp án điền vào chỗ trống trong câu sau: “Vi khuẩn phản nitrat biến đổi ....thành .....”

A. NH 4 + ; N 2 .

B.  NO 3 - ;  N 2 .

C.  NH 4 + ;  NO 3 - .

D.  N 2 ;  NO 3 - .

Công thức chung của amino axit no, mạch hở, có hai nhóm cacboxyl và một nhóm amino là:

A. C_nH_2n+1NO₂ 

B. C_nH_2n-1NO₄ 

C. C_nH_2nNO₄ 

D. C_nH_2n+1NO₄