Trong các mệnh đề sau, mệnh đề nào đúng?

A. Số đỉnh và số mặt của một hình đa diện luôn bằng nhau;

B. Tồn tại hình đa diện có số cạnh và số mặt bằng nhau.

C. Tồn tại hình đa diện có số cạnh bằng nhau;

D. Tồn tại hình đa diện có số đỉnh và số mặt bằng nhau;

Đốt cháy hoàn toàn 100 ml hỗn hợp gổm đimetylamin và 2 hiđrocacbon là đổng đẳng kế tiếp thu được 140 ml  CO 2  và 250 ml hơi nước (các khí đo ở cùng điểu kiện). Công thức phân tử của 2 hiđrocacbon?

A.  C 2 H 4   và   C 3 H 6

B.  C 2 H 2   và   C 3 H 4

C.  CH 4   và   C 2 H 6

D.  C 2 H 6   và   C 3 H 8

Question 2:

(1) Player
(2) When
(3) And
(4) Prize
(5) Hard
(6) Hope

Question 1:

Ex 1: Tires can be recycled to make pipes and floor coverings.
Ex 2: No, they can't
Ex 3: Thing to reuse :
- Reuse newspaper, interesting magazines, and other paper products by using them as wrapping paper.
- Reuse your old electronics.
Thing to recycle :
- Recycle metal cans, bottle, ....
- Recylcle mix paper.
Ex 4: Lạc đề nha bạn
Ex 5: Yes, it is

VIII/ Read the following passage on commuting, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 61 to 70.

After two decades of growing student enrollments and economic prosperity , business schools in the United States have started to face harder times. Only Harvard’s MBA School has shown a substantial increase in enrollments in recent years. Both Princeton and Stanford have seen decreases in their enrollments. Since 1990, the number of people receiving Masters in Business Administration (MBA) degrees, has dropped about 3 percent to 75,000, and the trend of lower enrollment rates is expected to continue.

There are two factors causing this decrease in students seeking an MBA degree. The first one is that many graduates of four-year colleges are finding that an MBA degree does not guarantee a plush job on Wall Street or in other financial districts of major American cities . Many of the entry-level management jobs are for students graduating with Master of Arts degrees in English and the humanities as well as those holding MBA degrees. Students have asked the question, “ Is an MBA degree really what I need to be best prepared for getting a good job?” The second major factor has been the cutting of American payrolls and the lower number of entry-level jobs being offered. Business needs are changing , and MBA schools are struggling to meet the new demands.

 The first paragraph is mainly concerned with which of the following?

A. factors contributing to the decline in MBA students 

B. Two decades of hard times for business schools 

C. The difference between Harvard, Princeton, and Stanford 

D. A current trend affecting the nation’s business schools

Read the following passage and mark the letter A, B, C or D to indicate the correct answer.

Although they are an inexpensive supplier of vitamins, minerals and high- quality protein, eggs, also contain a high level of blood cholesterol, one of the major causes of heart diseases. One egg yolk, in fact, contains a little more than two- thirds of the suggested cholesterol limit. This knowledge has driven egg sales to plummet in recent years, which in turn has brought about the development of several alternatives to eating regular eggs. One alternative is eating substitute eggs. These egg substitutes are not really eggs, but they look somewhat like eggs when they are cooked. They have the advantage of having low cholesterol rates, and they can be scrambled or used in baking. One disadvantage, however, is that they are not good for frying, poaching or boiling. A second alternative to regular eggs is a new type of egg, sometimes called “designer” eggs. These eggs are produced by hens that are fed low- fat diets consisting of ingredients such as canola oil, flax and rice bran. In spite of their diet, however, these hens produce eggs that contain the same amount of cholesterol as regular eggs. Yet, the producers of these eggs claim that eating their eggs will not raise the blood cholesterol in humans.

Egg producers claim that their product has been portrayed unfairly. They cite scientific studies to back up their claim. And, in fact, studies on relationship between eggs and human cholesterol levels have brought mixed result. It may be that it is not the type of eggs that is the main determinant of cholesterol but the person who is eating the eggs. Some people may be more sensitive to cholesterol derived from food than other people. In fact, there is evidence that certain dietary fats stimulate the body’s production of blood cholesterol. Consequently, while it still makes sense to limit one’s intake of eggs, even designer eggs, it seems that doing this without regulating dietary fat will probably not help reduce the blood cholesterol level.

According to the author, which of the following may reduce blood cholesterol?

A. Reducing egg intake but not fat intake

B. Increasing egg intake and fat intake

C. Decreasing egg intake and fat intake

D. Increasing egg intake but not fat intake

Một loài có bộ NST 2n=14, khi giảm phân thấy có 3 cặp NST xảy ra trao đổi chéo tại 1 điểm và 1 cặp bị rối loạn phân li, các cặp NST còn lại giảm phân bình thường. Số loại trứng tối đa của loài trên là:

A. 768 

B. 1256 

C. 1536 

D. 1024 

Chọn lọc tự nhiên làm thay đổi tần số alen trong quần thể bởi vì một số__________ tồn tại và sinh sản thành công hơn.

A. alen

B. locut 

C. vốn gen

D. cá thể

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 43 to 50

Pollution emitted in industrial areas represents a threat to human health and the surrounding natural resources. We have a tendency to believe that the production processes are the only source of environmental damage, and often forget about the possible long-term effects of harmful production practices. We may think that the closure of these huge industrial areas would improve the quality of the environment. Unfortunately, this ignores the threat of the remaining waste, which is abandoned and poorly stored. It represents an even bigger danger because it stands neglected as it degrades and leaks into the earth without any control at all.

Changes in the water chemistry due to surface water contamination can affect all levels of an ecosystem. It can affect the health of lower food chain organisms and, consequently, the availability of food up through the food chain. It can damage the health of wetlands and damage their ability to support healthy ecosystems, control flooding, and filter pollutants from storm water runoff. The health of animals and humans are affected when they drink or bathe in contaminated water. In addition water-based organisms, like fish and shellfish, can pile up and concentrate contaminants in their bodies. When other animals or humans eat these organisms, they receive a much higher dose of contaminant than they would have if they had been directly exposed to the original contamination.

Contaminated groundwater can badly affect animals, plants and humans if it is removed from the ground by manmade or natural processes. Depending on the study of rocks of the area, groundwater may rise to the surface through springs or seeps, flow sideways into nearby rivers, streams, or ponds, or sink deeper into the earth. In many parts of fhe world, groundwater is pumped out of the ground to be used for drinking, bathing, other household uses, agriculture, and industry.

Contaminants in the soil can harm plants when they take up the contamination through their roots. Eating, breathing in, or touching contaminated soil, as well as eating plants or animals that have piled up soil contaminants can badly affect the health of humans and animals.

Air pollution can cause breathing-related problems and other bad health effects as contaminants are absorbed from the lungs into other parts of the body. Certain air contaminants can also harm animals and humans when they contact the skin. Plants rely on breathing for their growth and can also be affected by exposure to contaminants moved in the air.

Question:Which of the followings affect an ecosystem as the whole?

A. Surface water contamination

B. Soil contamination

C. Groundwater contamination

D. Air contamination

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 36 to 42.

Successful students often do the followings while studying. First, they have an overview before reading. Next, they look for important information and pay greater attention to it (which often needs jumping forward or backward to process information). They also relate important points to one another. Also, they activate and use their prior knowledge. When they realize that their understanding is not good, they do not wait to change strategies. Last, they can monitor understanding and take action to correct or “fix up” mistakes in comprehension.

Conversely, students with low academic achievement often demonstrate ineffective study skills. They tend to assume a passive role, in learning and rely on others (e.g., teachers, parents) to monitor their studying, for example, low-achieving students often do not monitor their understanding of content; they may not be aware of the purpose of studying; and they show little evidence of looking back, or employing “fix-up” strategies to fix understanding problems. Students who struggle with learning new information seem to be unaware that they must extent effort beyond simply reading the content to understand and remember it. Children with learning disabilities do not plan and judge the quality of their studying. Their studying may be disorganized. Students with learning problems face challenges with personal organization as well. They often have difficulty keeping track of materials and assignments, following directions, and completing work on time. Unlike good studiers who employ a variety of study skills in a flexible yet purposeful manner, low-achieving students use a restricted range of study skills. They cannot explain why good study strategies are important for learning; and they tend to use the same, often ineffective study approach for all learning tasks, ignoring task content, structure or difficulty.

Question:The underlined pronoun “They” in the last sentence refers to______.

A. study strategies

B. study skills

C. low-achieving students

D. good studiers