题目内容
（请给出正确答案）
When the AIDS virus attacks our defense system, ______.
A．it starts to destroy our white brood cells
B．we begin to feel tired
C．it means we will die very soon
D．our white blood cells can cotrol it
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But doctors say evidence also shows there is no reason for persons to become terrified by the disease. The AIDS virus is spread during sex with an infected partner, or by infected blood. But doctors say their studies show the disease is not spread through normal, close social activities.
A study by one research team was printed in the New England Journal of Medicine. The doctors studied one-hundred-one family members who lived with AIDS and lived in crowded conditions. The family members shared many personal goods with the patients. These included toothbrushes, drinking glasses, beds, towels and toilets.
Doctors said only one family member—a five-year-old girl—got the AIDS virus. They note, however, that the girl's mother had the disease. They believe the girl probably was born with the virus. No other family member in the study got the AIDS virus or showed any signs of the disease.
The head of the study, Gerald Friedland, said if the disease is not easily spread in crowded homes, it also will not spread easily in factories, offices, schools and other public places. (67) Doctor Friedland said the study also shows there is no reason to punish AIDS patients and to force them to live separately from other persons.
American health officials recently warned, however, that some health care workers should take special care. The report noted the AIDS virus is carried in blood and other body fluids. It said health care workers should put protective covers over their eyes and skin during medical operations, dental work, or other times when the patient may bleed.
(68)In the United States, most AIDS patients are homosexual people, people taking drugs, people who used infected needles, and persons who received infected blood. More recent studies show the AIDS virus also can be spread during heterosexual(异性的)relations. It can spread either from the man to the woman, or from the woman to the man.
Doctors say there is no reason for people to be frightened about AIDS because______.
A．it is not deadly
B．few people are infected with AIDS
C．the AIDS virus is not spread in everyday social activities
D．the AIDS virus is not spread during sex
According to experts, the test for AIDS is______.
A．100 percent certainty correlated with the presence of the virus in cultures
B．ambiguous because even they themselves are not certain
C．inaccurate because there are consistently confusing results
D．not correlated with the presence of the virus
The fifth paragraph is mainly about ______.
A．the results of an AIDS infection
B．the possible symptoms of an AIDS infection
C．how the AIDS virus is spread
D．the diseases AIDS patients easily have
The study of 101 family members who lived with AIDS patients shows that______.
A．the AIDS is not spread by personal goods
B．women are more likely to get the AIDS virus than men
C．married people are less likely to get AIDS than unmarried ones
D．the AIDS virus is passed by drinking glasses
There is no cure for AIDS and no vaccine(疫苗) medicine to prevent it. However, researchers know much more about AIDS than they did just a few years ago. We now know that AIDS is caused by a virus. The virus invades healthy cells including white blood cells that are part of our defense system against disease. It takes control of the healthy cell's genetic(遗传的) material and forces the cell to make a copy of the virus. The cell then dies. And the viral particles move on to invade and kill more healthy cells.
The AIDS virus is carried in a person's body fluids. The virus can be passed sexually or by sharing instruments used to take intravenous(静脉内的) drugs. It also can be passed in blood products or from a pregnant woman with AIDS to her developing baby.
Many stories about the spread of AIDS are false. You cannot get AIDS by working or attending school with someone who has the disease. You cannot get it by touching, drinking glasses or other objects used by such persons. Experts say no one has gotten AIDS by living with, caring for or touching an AIDS patient.
There are several warning signs of an AIDS infection. They include always feeling tired, unexplained weight loss and uncontrolled expulsion of body wastes(大小便失禁). Other warnings are the appearance of white areas on the mouth, dark red areas of skin that do not disappear and a higher than normal body temperature.
Concerning the ways the AIDS virus can be passed, which of the following statements is wrong？
A．An AIDS mother can pass on the virus to her unborn child.
B．The AIDS virus can be passed on through infected blood.
C．The AIDS virus can be passed on by shaking hands and sharing belongings.
D．The AIDS virus is passed sexually.
From the last sentence of Para. 5, we can learn that we have no reason to______.
A．stop meeting AIDS patients in public places
B．stop living with AIDS patients
C．fear that AIDS can be passed from a mother to a baby
D．fear that the AIDS virus can be passed during sex
Most AIDS researchers agree that vaccines will be the only effective way to control a virus that has killed 28 million people and infected 42 million more worldwide.
Two dozen other vaccines are being tested on 12,000 human volunteers, but none has advanced as far as VaxGen's, and any successful candidate is years away. Officials at Brisbane, Calif-based VaxGen said the Thai results underscored again how wily AIDS is in thwarting the immune system. The findings also show "how important it is for the international public health community to redouble the effort to develop an effective vaccine," President Dr. Donald Francis said.
VaxGen's vaccine, like most others being tested, did not contain the virus itself and cannot cause AIDS. Instead, the vaccine contained small, manmade genetic bits of the virus that scientists had hoped would provoke an immune response strong enough to stop the virus from invading healthy cells. Three years ago, the company enrolled 2,546 people in and around Bangkok who were at high risk for HIV because they habitually swapped needles to inject drugs. Half were given the experimental vaccine and half were given a placebo. All volunteers were given extensive risk-reduction counseling, the company said. In the end, the vaccine offered no greater protection: 105 people given the placebo became infected with HIV, while 106 people given the vaccine tested positive. In February, VaxGen announced its vaccine was ineffective against a different AIDS strain found in North America.
The failure of this experimental vaccine reinforces the hardness of anti-AIDS battle, and the ultimate success seems to emerge years later. However, mankind is not so vulnerable to be completely defeated by AIDS.
Where is the experimental AIDS vaccine tested？
A．In Thailand
B．In North America
C．At Brisbane
D．In Africa
Health workers were warned to take special care when the patient bleeds because______.
A．AIDS can be passed by touching the patient's body
B．AIDS can be spread by touching the patient's skin
C．AIDS virus can be carried in blood or other body fluids
D．AIDS virus is easily spread in eye and skin
Part A
Directions: Read the following four texts. Answer the questions below each text by choosing A, B, C or D. (40 points)
Could HIV, the virus that causes AIDS, be weakening？ The results of a study conducted in Belgium, at the Institute of Tropical Medicine in Antwerp, seem to suggest that in one corner of the world it might be. The report, published in the latest issue of AIDS, a specialist journal, concludes that HIV's ability to replicate (known technically as its virulence) may have decreased since the start of the pandemic. Kevin Aden, the lead author of the paper, stresses that the study is based on a small set of samples and does not prove that HIV's virulence is attenuating around the world. However, it does offer new insights into the evolution of the disease.
Dr. Arien looked at 24 blood samples collected from untreated patients attending an HIV/ AIDS clinic in Antwerp. A dozen of these samples were taken between 1986 and 1989; the other 12 were collected between 2002 and 2003. First, he analyzed the samples to find their viral load (the number of virus particles per cubic centimeter) and the subtype of virus involved. In Europe and North America, the predominant subtype is B; in sub-Saharan Africa, where the epidemic is at its worst, the predominant subtype is C. Most of Dr. Arien's samples were of subtype B. Having done this analysis, he paired the samples off for a series of replicative "duels". Each sample from the earlier series was matched with the most similar one from the later series, and they were placed in identical cell cultures to see which would multiply the most. The result was that 75% of the viruses from 2002-03 were less virulent than apparently similar counterparts from 1986-89—a statistically significant observation.
Dr. Arien's caution is sensible, at least until someone replicates the work elsewhere. But his conclusion is not necessarily surprising. Such viral attenuation, as it is known, is one way that vaccines are produced.
What causes attenuation in wild viruses, though, is a matter of speculation. Dr Arien believes that in this case the attenuation could be the result of what he calls "serial genetic bottlenecks" during transmission from host to host. These act to reduce the genetic diversity (and thus the replicative fitness) of the virus. Genetic diversity is known to be an important component of HIV's virulence. But what might cause the bottlenecks is still unclear.
A second reason for caution besides the small size of the study is, as Geoffrey Garnett, a professor of microparasite epidemiology at Imperial College, London, points out, that the ability of a virus to infect cells in a test-tube is not the same as its ability to cause disease and death in a human host. Nevertheless, Dr Aden's result is intriguing, and surely worth following up in a larger piece of research.
The word "attenuating"(Paragraph 1) most probably means
A．weakening.
B．accentuating.
C．accelerating.
D．increasing.
