Tripeptit tạo ra từ aminoaxit no hở chứa 1 nhóm NH₂ và 1 nhóm COOH có công thức chung là: 

A. C_2nH_4n-1O₃N₃ 

B. C_3nH_{6n -1}O₃N₃ 

C. C_3nH_6n-1O₄N₃ 

D. C_4nH_8n-3O₉N₄

Read the following passage and choose the best answer for each blank.

Parents whose children show a special interest in a particular sport have a difficult decision to (36)__________about their children’s career. Should they (37)__________their children to train to become top sportsmen and women? For many children it (38)__________starting very young and school work, going out with friends and other (39)__________have to take second place. It’s very difficult to explain to a young child why he or she has to train for five hours a day, even at the weekend, when (40)__________of his or her friends are playing.

Another problem is of course money. In many countries money for training is (41)__________from the government for the very best young sportsmen and women. If this help cannot be given, it means that it is

the parents (42)__________have to find the time and the money to support their child’s development- and sports clothes, transport to competitions, special equipment etC. can all be very expensive.

Many parents tire understandably (43)__________that it is dangerous to start serious training in a sport at an early age. Some doctors agree that young (44)__________may be damaged by training before they are properly developed. Professional ữainers, however, believe that it is only by starting young that you can reach the top as a successful sports person. What is clear is that very (45)__________people reach the top and both parents and children should be prepared for failure even after many years of training.Question 36

A. do

B. plan

C. make

D.prepare

Cho dung dịch Ba(HCO₃)₂ lần lượt vào các dung dịch: CaCl₂, Ca(NO₃)₂, NaOH, Na₂CO₃, KHSO₄, Na₂SO₄, Ca(OH)₂, H₂SO₄, HCl. Số trường hợp đồng thời tạo ra kết tủa và có khí bay ra là: 

A. 5.

B. 2

C. 6.

D. 3

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.

Question 50. My sister is good at cooking. My brother is bad at it.

A. My sister is good at cooking, or my brother is bad at it.

B. My sister is good at cooking, for my brother is bad at it.

C. My sister is good at cooking, but my brother is bad at it.

D. My sister is good at cooking, so my brother is bad at it.