单选题The advertising industry has resorted to self-regulation in a serious effort to {{U}}curtail{{/U}} not only bad taste but also misrepresentation and deception in copy and illustrations.

单选题Franklin Delano Roosevelt was the U.S. President when many businesses were______ during the Great Depression.

单选题The old lady sitting ______ her had her handbag open.

单选题Spirit failed to talk to its controllers probably because of______.

单选题It is necessary that we ______ have a good command of English at college.

单选题All ______ is a continuous supply of fuel oil.

单选题It is difficult for us to explain phenomena that we have little or ______ direct knowledge.

单选题Sports, ______ perhaps you don't like very much, may make you strong.

单选题In addition to being physically sick, my dad was in the midst of a nervous ______, though none of us knew to call it that at the time.

单选题To qualify for such a position, the native would first have to receive specialized training, and this is ______. A. refused B. discouraged C. denied D. forbidden

单选题 Directions: For this part, you are allowed 30 minutes to write an essay entitled Man and Artificial Intelligence by commenting on the saying, 'The real problem is not whether machines think but whether men do.' You should write at least 150 words but no more than 200 words.

单选题The washing machines sold in our shop will be ______ for one year.

单选题 Metals we found in the earth ______ iron, lead and copper.

单选题Her dog ran out of the yard _______the old lady opened the gate.

单选题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.

单选题The rapid development of communications technology is transforming the ______ in which people communicate across time and space.

单选题______near-perfect English language skills, the students were keen to explore every aspect of Australian culture, from Aussie eating customs to family and student life, popular culture, the natural landscape and the ever-popular Australian native animals.