Tính diện tích toàn phần của hình trụ có bán kính đáy a và đường cao  a 3

A.  2 πa 2 3 - 1

B. πa 2 3

C. πa 2 3 + 1

D. 2 πa 2 3 + 1

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 26 to 34.

Although noise, commonly defined as unwanted sound, is a widely recognized form of pollution, it is very difficult to measure because the discomfort experienced by different individuals is highly subjective and, therefore, variable. Exposure to lower levels of noise may be slightly irritating, whereas exposure to higher levels may actually cause hearing loss. Particularly in congested urban areas, the noise produced as a by-product of our advancing technology causes physical and psychological harm, and detracts from the quality of life for those who are exposed to it.

Unlike the eyes, which can be covered by the eyelids against strong light, the ear has no lid, and is, therefore, always open and vulnerable; noise penetrates without protection. Noise causes effects that the hearer cannot control and to which the body never becomes accustomed. Loud noises instinctively signal danger to any organism with a hearing mechanism, including human beings. In response, heartbeat and respiration accelerate, blood vessels constrict, the skin pales, and muscles tense. In fact, there is a general increase in functioning brought about by the flow of adrenaline released in response to fear, and some of these responses persist even longer than the noise, occasionally as long as thirty minutes after the sound has ceased. Because noise is unavoidable in a complex, industrial society, we are constantly responding in the same way that we would respond to danger. Recently, researchers have concluded that noise and our response may be much more than an annoyance. It may be a serious threat to physical and psychological health and well-being, causing damage not only to the ear and brain but also to the heart and stomach. We have long known that hearing loss is America's number one nonfatal health problem, but now we are learning that some of us with heart disease and ulcers may be victims of noise as well. Fetuses exposed to noise tend to be overactive, they cry easily, and they are more sensitive

to gastrointestinal problems after birth. In addition, the psychic effect of noise is very important. Nervousness, irritability, tension, and anxiety increase affecting the quality of rest during sleep, and the efficiency of activities during waking hours, as well as the way that we interact with each other

Look at the verb accelerate in paragraph 3. Which of the following is the closest in meaning to _____.

A. decrease

B. alter

C. increase

D. release

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 27 to 36.

Federal Express is a company that specializes in rapid overnight delivery of high-priority packages. The first company of its type, Federal Express was founded by the youthful Fred Smith in 1971, when he was only 28 years old. Smith had actually developed the idea for the rapid delivery service in a term paper for an economics class when he was a student at Yale University. The term paper reputedly received a less-than-stellar grade because of the infeasibility of the project that Smith had outlined. The model that Smith proposed had never been tried; it was a model that was efficient to operate but at the same time was very difficult to institute.

Smith achieved efficiency in his model by designing a system that was separate from the passenger system and could, therefore, focus on how to deliver packages most efficiently. His strategy was to own his own planes so that he could create his own schedules and to ship all packages through the hub city of Memphis, a set-up which resembles the spokes on the wheel of a bicycle. With this combination of his own planes and hub set-up, he could get packages anywhere in the United States overnight.

What made Smith's idea difficult to institute was the fact that the entire system had to be created before the company could begin operations. He needed a fleet of aircraft to collect packages from airports every night and deliver them to Memphis, where they were immediately sorted and flown out to their new destinations; he needed a fleet of trucks to deliver packages to and from the various airports; he needed facilities and trained staff all in place to handle the operation. Smith had a $4 million inheritance from his father, and he managed to raise an additional $91 million dollars from venture capitalists to get the company operating.

When Federal Express began service in 1973 in 25 cities, the company was not an immediate success, but success did come within a relatively short period of time. The company lost $29 million in the first 26 months of operations. However, the tide was to turn relatively quickly. By late 1976, Federal Express was carrying an average of 19.000 packages per night and had made a profit of $3,6.

How long did it take Federal Express to become profitable?

A. One year

B. Three years

C. Six years

D. Two months

Tình huống thể hiện quyền tự do ngôn luận: a), b), c).