题目内容
I was ______ by an unexpected caller that afternoon, so I failed to turn up at the meeting
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The last class coming to an end, the students, with meal boxes and spoons in hands, ______
Americans are proud of their variety and individuality, yet they love and respect few things more than a uniform, whether it is the uniform. of an elevator operator or the uniform. of a five-star general. Why are uniforms so popular in the United States？ Among the arguments for uniforms, one of the first is that in the eyes of most people they look more professional than civilian clothes. People have become conditioned to expect superior quality from a man who wears a uniform. The television repairman who wears uniform. tends to inspire more trust than one who appears in civilian clothes. Faith in the skill of a garage mechanic is increased by a uniform. What easier way is there for a nurse, a policeman, a barber, or a waiter to lose professional identity than to step out of uniform？
Uniforms aim have many practical benefits. They save on other clothes. They save on laundry bills. They are tax-deductible. They are often more comfortable and more durable than civilian clothes.
Primary among the arguments against uniforms is their lack of variety and the consequent loss of individuality experienced by people who must wear them. Though there are many types of uniforms, the wearer of any particular type is generally stuck with it, without change, until retirement. When people look alike, they tend to think, speak, and act similarly, on the job at least.
Uniforms also give rise to some practical problems. Though they are long-lasting, often their initial expense is greater than the cost of civilian clothes. Some uniforms are also expensive to maintain, requiring professional dry cleaning rather than the home laundering possible with many types of civilian clothes.
It is surprising that Americans who worship variety and individuality ______.
Part A
Directions: Read the following three texts. Answer the questions on each text by choosing A, B, C or D. Mark your answers on ANSWER SHEET 1.
Why were the Wright brothers able to succeed in an effort at which so many others had failed？ Many explanations have been mentioned, but three reasons are most often cited. First, they were a team. Both men worked congenially and cooperatively, talked incessantly about the possibility of manned flight, and served as a conscious source of inspiration and encouragement to each other.
Both were glider pilots. Unlike some other engineers who experimented with the theories of flight, they experienced the practical aspects of aerodynamics by building and flying in kites and gliders. They had realized from their experiments that the most serious challenge in manned flight would be stabilizing and maneuvering the aircraft once it was airborne. While others concentrated their efforts on the problem of achieving lift for take-off, they were focusing on developing a three axis control for guiding their aircraft.
In addition, the Wright brothers had designed more effective wings for the airplane than had been previously engineered. Using a wind tunnel, they tested more than two hundred different wing designs, recording the effects of slight variations in shape on the pressure of air on the wings. The data from theses experiments allowed the Wright brothers to construct a superior wing for their air craft. In spite of these advantages, however, the Wright brothers might not have succeeded had they not been born at precisely the opportune moment in history. Attempts to achieve manned flight in the early nineteenth century were doomed because the steam engines that powered the aircrafts were so heavy in proportion to the power that they produced. But by rite end of the nineteenth century, when the brothers were experimenting with engineering options, a relatively light internal combustion engine had already been invented, and they were able to bring the ratio of weight to power within acceptable limits for flight.
What is the passage mainly talking about？
Since the early 1980s, scientists have revealed some 40 human genes involved in cancer. These genes are essential for normal growth, but can be subverted to cause a tumor.
Dr. Jorge Yunis of the University of Minnesota Medical School in Minneapolis has found that 70 percent of oncogenes, or cancer-causing genes, are located near inherited weak points on chromosomes(染色体). Varying from individual to individual, vulnerable to chemical carcinogens(致癌剂), X rays and other cancer-inducing agents.
"If a chromosome snaps apart in the immediate vicinity of an oncogene," says Yunis, "normal genetic control mechanisms could break down and the stage would be set for the formation of cancer." Younis has shown that such a sequence occurs at the beginning of numerous leukemias (白血病), lymphomas(淋巴瘤) and some tumors of the lung, colon(结肠) and breast.
Yunis and other investigators have found that petroleum-based products--notably pesticides and insecticides-damage specific sites on at least two of the 23 pairs of human chromosomes that carry genetic information. Similarly, tobacco smoke tends to attack a part of another chromosome.
From paragraph 1, we know that some 40 genes involving in cancer are ______. ()
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