Phá ngoặc:

=2a²+b²+c²/2a²+b²+c² + 2b²+c²+a²/2b²+a²+c² + 2c²+b²+a²/2c²+a²+b²

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^=0>8

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

When you see your teacher approaching you, a slight wave to attract his attension is appropiate

A. coming nearer to

B. leaving 

C. pointing at 

D. looking up to

Chọn phát biểu đúng.

A. Thủy phân vinyl axetat trong môi trường kiềm thu được ancol

B. Công thức phân tử của tristearin là C₅₇H₁₀₈O₆ 

C. Phản ứng thủy phân chất béo trong môi trường kiềm là phản ứng một chiều

D. Ở điều kiện thường triolein là chất rắn không tan trong nước, nhẹ hơn nước

Một xe tải lần lượt chở các vật liệu sau với khối lượng bằng nhau: thép lá, gỗ và vải. Trong trường hợp nào thì xe khó bị đổ nhất? dễ bị đổ nhất?

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.

It was such strong coffee that he couldn’t drink it.

A. The coffee was too strong for him to drink

B. He couldn’t drink the coffee although the coffee was so strong.

C. He couldn’t drink too strong coffee before.

D. The strong coffee made him able to drink it.

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

You will have to ________________ your holiday if you are too ill to travel.

A. call off

B. cut down

C. back off

D. put aside

* Read the following passage and mark the letter A, R, C, or D on your answer sheet to indicate the correct answer to each of the questions from 24 to 30.

  People have been donating blood since the early twentieth century to help accident victims and patients undergoing surgical procedures. Usually a pint of whole blood is donated, and it is then divided into platelets, white blood cells, and red blood cells. People can donate blood (for red blood cells) about once every two months.

  Transfusing the blood from the donor to the recipient is straightforward. It involves taking the blood from a donor’s arm vein by means of a hypodermic syringe. The blood flows down from the container by gravity. This is a slow process and may last as long as 2 hours to complete the infusion of blood into the recipient. The patient is protected from being infected during the transfusion. Only sterile containers, tubing, and needles are used, and this helps ensure that transfused or stored blood is not exposed to disease causing bacteria.

  Negative reactions to transfusions are not unusual. The recipient may suffer an allergic reaction or be sensitive to donor leukocytes. Some may suffer from an undetected red cell incompatibility. Unexplained reactions are also fairly common. Although they are rare, other causes of such negative reactions include contaminated blood, air bubbles in the blood, overloading of the circulatory system through administration of excess blood, or sensitivity to donor plasma or platelets.

  Today, hospitals and blood banks go to great lengths to screen all blood donors and their blood. All donated blood is routinely and rigorously tested for diseases, such as HIV, hepatitis B, and syphilis. When the recipient is a newborn or an infant, the blood is usually irradiated to eliminate harmful elements. Donated blood is washed, and the white blood cells and platelets removed.

  Storing the blood sometimes requires a freezing process. To freeze the red blood cells, a glycerol solution is added. To unfreeze the, the glycerolis removed. The ability to store blood for long periods has been a boon to human health.

What answer choice is closest in meaning to the word “undetected”?

A. not illustrated

B. not captured

C. not found

D. not wanted