Cho hợp chất X mạch hở, có công thức phân tử C₃H₇O₂N. Cho 5,34 gam X tác dụng hoàn toàn với 80 gam dung dịch NaOH 4%; cô cạn dung dịch sau phản ứng, thu được 6,44 gam chất rắn khan. Công thức cấu tạo của X là 

A. H₂NCH₂COOCH₃

B. CH₂=CHCOONH₄

C. H₂NCH₂CH₂COOH

D. HCOONH₃CH=CH₂

Mark the letter A, B, C or B on your answer sheet to indicate the correct answer to each of the following questions.

Some species of rare animals are in _________ of extinction.

A. danger

B. dangerous

C. danger

D. endanger

X là amino axit có công thức H₂NC_nH_2nCOOH, Y là axit cacboxylic no, đơn chức, mạch hở. Cho hỗn hợp E gồm peptit Ala-X-X và Y tác dụng vừa đủ với 450 ml dung dịch NaOH 1M, thu được m gam muối Z. Đốt cháy hoàn toàn Z cần 25,2 lít khí O₂ (đktc), thu được N₂, Na₂CO₃ và 50,75 gam hỗn hợp gồm CO₂ và H₂O. Khối lượng của muối có phân tử khối nhỏ nhất trong Z là

A. 14,55 gam

B. 12,30 gam

C. 26,10 gam

D. 29,10 gam

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 35 to 42.

  When another old cave is discovered in the south of France, it is not usually news. Rather, it is an ordinary event. Such discoveries are so frequent these days that hardly anybody pays heed to them. However, when the Lascaux cave complex was discovered in 1940, the world was amazed.

  Painted directly on its walls were hundreds of scenes showing how people lived thousands of years ago. The scenes show people hunting animals, such as bison or wild cats. Other images depict birds and, most noticeably, horses, which appear in more than 300 wall images, by far outnumbering all other animals.

  Early artists drawing these animals accomplished a monumental and difficult task. “They” did not limit themselves to the easily accessible walls but carried their painting materials to spaces that required climbing steep walls or crawling into narrow passages in the Lascaux complex.

  Unfortunately, the paintings have been exposed to the destructive action of water and temperature changes, which easily wear the images away. Because the Lascaux caves have many entrances, air movement has also damaged the images inside. Although they are not out in the open   air, where natural light would have destroyed them long ago, many of the images have deteriorated and are barely recognizable. To prevent further damage, the site was closed to tourists in 1963, 23 years after it was discovered.

Based on the passage, what is probably true about the south of France?

A. It is home to rare animals.

B. It is known for horse-racing events,

C. It has attracted many famous artists.

D. It has a large number of caves.

Cho từng chất: Fe, FeO, Fe(OH)₂, Fe(OH)₃, Fe₃O₄, Fe₂O₃, Fe(NO₃)₂, Fe(NO₃)₃, FeSO₄, Fe₂(SO₄)₃,FeCO₃ lần lượt vào phản ứng với HNO₃ đặc nóng dư. Số phản ứng thuộc loại phản ứng oxit hóa khử là:

A. 5

B. 6

C. 8

D. 7

Cho Amoniac tác dụng với các chất sau: Khí Cl₂, khí O₂, dung dịch H₂SO₄, CuO nung nóng, khí CO₂, dung dịch AlCl₃, dung dịch CuSO₄, khí HCl. Số chất phản ứng là:

A. 6                           

B. 7                          

C. 8                           

D. 5

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word for each of the blanks from 66 to 75.

Sudoku

Are you a fan of the popular logical puzzle that (66) x by the name Sudoku? Even if you’re not, the chances are you know somebody who is. Once (67) x known outside Japan, this addictive brain teaser has become a common feature of newspaper puzzle pages all over the world.

Sudoku’s great success (68) x much to its simplicity. The game (69) x for neither mathematical ability nor (70) x knowledge and there are just a few sentences of straightforward instructions to read before you can play. The only skill required is the ability to recognize the difference between nine different symbols, and these don’t even have to be numbers.

Some clever marketing has helped the game. Western newspapers worked hard at promoting the game. Without this, it is unlikely that it would have (71) x off and become quite such a runaway success. The same also (72) x from its Japanese name that made people in many parts of the world (73) x . It as a superior kind of puzzle compared to those you usually find in newspapers and magazines.

But the popularity of Sudoku reached a peak in 2006, if the number of (74) x on one leading website is anything to go by. Newspapers responded by (75) x up with new kinds of logical puzzles, all with simple rules and Japanese names. But for true Sudoku fans, only the real thing will do.

Điền vào ô 70

A. general

B. normal

C. usual

D. ordinary

Cặp cơ quan nào sau đây là bằng chứng chứng tỏ sinh vật tiến hoá theo hướng đồng quy tính trạng?

A. Cánh chim và cánh bướm

B. Ruột thừa của người và ruột tịt ở động vật

C. Tuyến nọc độc của rắn và tuyến nước bọt của người

D. Chân trước của mèo và cánh dơi

Một khe hẹp F phát ánh sáng đơn sắc, bước sóng λ = 600mm chiếu sáng hai khe F1, F2 song song với F và cách nhau 1,2mm. Vân giao thoa được quan sát trên một màn M song song với mặt phẳng chứa F1, F2 và cách nó 0,5m. Tính khoảng vân.