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.

It used to be that people would drink coffee or tea in the morning to pick them up and get them going for the day. Then cola drinks hit the market. With lots of caffeine and sugar, these beverages soon became the pick-me-up of choice for many adults and teenagers. Now drink companies are putting out so-called "energy drinks." These beverages have the specific aim of giving tired consumers more energy.

One example of a popular energy drink is Red Bull. The company that puts out this beverage has stated in interviews that Red Bull is not a thirst quencher. Nor is it meant to be a fluid replacement drink for athletes. Instead, the beverage is meant to revitalize a tired consumer’s body and mind. In order to do this, the makers of Red Bull, and other energy drinks, typically add vitamins and certain chemicals to their beverages. The added chemicals are like chemicals that the body naturally produces for energy. The vitamins, chemicals, caffeine, and sugar found in these beverages all seem like a sure bet to give a person energy.

Health professionals are not so sure, though. For one thing, there is not enough evidence to show that all of the vitamins added to energy drinks actually raise a person’s energy level. Another problem is that there are so many things in the beverages. Nobody knows for sure how all of the ingredients in energy drinks work together.

Dr. Brent Bauer, one of the directors at the Mayo Clinic in the US, cautions people about believing all the claims energy drinks make. He says, - It is plausible if you put all these things together, you will get a good result.” However, Dr. Bauer adds the mix of ingredients could also have a negative impact on the body. - We just don’t know at this point,” he says.

According to the passage, what makes it difficult for researchers to know if an energy drink gives people energy?

A. Natural chemicals in a person’s body

B. The average age of the consumer

C. The number of beverage makers

D. The mixture of various ingredients

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

Researchers in the field of psychology have found that one of the best way to make an important decision, such as choosing a university to attend or business to invest in, involves the utilization of a decision worksheet. Psychologists who study optimization compare the actual decisions made by people to theretical ideal decisions to see how similar they are. Proponents of the worksheet procedure believe that it will yield optimal, that is, the best decisions. Although there are several variations on the exact format that worksheets cam take, they are all similar in their essential aspects.

 Worksheets require defining the problem in a clear and concise way and then listing all possible solutions to the problem. Next, the pertinent considerations that all possible solutions to the problem. Next, the pertinent considerations that will be affected by each decision are listed, and the relative importance of each consideration or consequence is determined. Each consideration is assigned a numerical value to reflect its relative importance. A decision is mathematically calculated by adding these values together. The alternative with the highest number of points emerges as the best decision.

 Since most important problems are multifaceted, there are several alternatives to choose from, each with unique advantages and disadvantages. One of the benefits of a pencil and paper decision-making procedure is that it permits people to deal with more variables than their minds can generally comprehend and remember. On the average, people can keep about seven ideas in their minds at once. A worksheet can be especially useful when the decision involves a large number of variables with complex relationships. A realistic example for many college students is the question "What will I do after graduation?" A graduate might seek a position that offers specialized training, pursue an advanced degree, or travel abroad for a year.

 A decision-making worksheet begins with a succinct statement of the problem that will also help to narrow it. It is important to be clear about the distinction between long-range and immediate goals because long-range goals often involve a different decision than short-range ones. Focusing on long-range goals, a graduating student might revise the question above to "What will I do after graduation that will lead to a successful career?"

The word "it" in paragraph 4 refers to

A. worksheet

B. problem

C. distinction

D. decision

She spent _________ her free time watching TV

A. a few

B. most of

C. a lot

D. most

 Để trang hoàng cho căn hộ của mình, chú chuột mickey quyết định tô màu một miếng bài hình vuông cạnh bằng 1, nó tô màu xám các hình vuông nhỏ được đánh số lần lượt là 1, 2, 3,…, n,…, trong đó cạnh của hình vuông kế tiếp bằng một nửa cạnh hình vuông trước đó. (hình dưới). Giả sử quy trình tô màu của Mickey có thể diễn ra vô hạn.

a. Gọi u n  là diện tích hình vuông màu xám thứ n. Tính u 1 ,   u 2 ,   u 3   v à   u n

b. Tính lim S n  với S n   =   u 1   +   u 2   +   u 3   + … +   u n