单选题About one quarter of the workers in the country are employed in factories.

单选题In the latter case the {{U}}outcome{{/U}} can be serious indeed.

单选题 下面有3篇短文，每篇短文后有5道题，每道题后面有4个选项。请仔细阅读短文并根据短文内容回答其后面的问题，从4个选项中选择1个最佳答案。{{B}}第一篇{{/B}} {{B}} Diseases of Agricultural Plants{{/B}} Plants, like animals, are subject to diseases of various kinds. It has been estimated that some 30,000 different diseases attack our economic plants; forty are known to attack com, and about as many attack wheat. The results of unchecked plant diseases are ail too obvious in countries that have marginal food supplies. The problem will soon be more widespread as the population of the world increases at its frightening rate. Even in countries that are now amply fed by thek agricultural products there could soon be food shortages. It is easy to imagine the consequences of some disastrous attack on one of the major crops; the resulting famines could kill millions of people, and the resulting hardship on other millions could cause political upheavals disastrous to the order of the world. Some plants have relative immunity to great many diseases, while others have a susceptibility to them. The tolerance of a particular plant changes as the growing conditions change. A blight may be but a local infection easily controlled; on the other hand it can attack particular plants in a whole region or nation. An example is the blight that killed virtually every chestnut tree in North America. Another is the famous potato blight in Ireland in the last century. As a result of that, it was estimated that one million people died of starvation and related ailments. Plant pathologists have made remarkable strides in identifying the pathogens of the various diseases. Bacteria may include invade a plant through an infestation of insect parasites carrying the pathogen. A plant can also be inoculated by man. Other diseases might be caused by fungus which attacks the plant in the form of a mold or smut or rust. Frequently such a primary infection will weaken the plant so that a secondary infection may result from its lack of tolerance. The symptoms shown may cause an error in diagnosis, so that treatment may be directed toward bacteria which could be the result of a susceptibility caused by primary virus infection.

单选题It is difficult to assess the importance of the decision.

单选题Which of the following is NOT true of chronic diseases in the US?

单选题Both princes gave up earthly wealth and power for the spiritual life. A. announced B. renounced C. denounced D. pronounced

单选题If we leave now, we should miss the rush hour.

单选题They are trying to Uidentify/U what is wrong with the present system.

单选题It is out of the question that the inspector will come tomorrow.A. impossibleB. possibleC. probableD. likely

单选题Althouse Bus Company pays much attention to

单选题It was a question of making sure that certain needs were addressed, notably in the pensions area. A. noticeably B. remarkably C. particularly D. significantly

单选题Charges for local telephone calls are Uoutrageous/U.

单选题{{B}}第三篇{{/B}} {{B}} New Attempts to Eradicate AIDS Virus{{/B}} A high-profile attempt to eradicate the AIDS virus in a few patients continues to show promise. But researchers won't know for a year or more whether it will work, scientist David Ho told journalists this Wednesday for the Fourth Conference in Viruses and Infections. "This is a study that's in progress," says Ho, head of the Aaron Diamond AIDS Research Center, New York. The study involves 20 people who started combinations of anti-HIV drugs very early in the course of the disease, within 90 days of their infections. They've been treated for up to 18 months. Four others have dropped out because of side effects or problems complying with the exacting drug system. The drugs have knocked the AIDS virus down to undetectable levels in the blood of all remaining patients. And, in the latest development, scientists have now tested lymph nodes and semen from a few patients and found no virus reproducing there, Ho says. "Bear in mind that undetectable does not equal absent," Ho says. Ho has calculated that the drugs should be able to wipe out remaining viruses--at least from known reservoirs throughout the body--in two to three years. But the only way to prove eradication would be to stop the drugs and see if the virus comes back. On Wednesday, Ho said he wouldn't ask any patient to consider that step before 2 years of treatment. And he emphasized that he is not urging widespread adoption of such early, aggressive treatment outside of trials. No one knows the long-term risks. But other scientists are looking at similar experiments. A federally funded study will put 300 patients on triple-drug treatments and then see if some responding well after six months can continue to suppress the virus on just one or two drugs, says researcher Douglas Richman of the University of California, San Diego. Some patients in that study 'also may be offered the chance to stop therapy after 18 months or more, he says.

单选题Compound microscopes have two separate lenses or sets of lenses. A. split B. equal C. detachable D. distinct

单选题{{B}}第三篇{{/B}} Joyce Sipes and Mary Ellen Dodge When Joyce Sipes was diagnosed with breast cancer in 1999, she shared the news immediately with her sister Mary Ellen Dodge. Mary Ellen was there for her--helping her through the terror, and the fear, and the thousand questions that are inevitably a part of hearing the word "cancer". Fortunately, a friend at work who had had a similar diagnosis highly recommended Alonzo Walker, MD, Medical College of Wisconsin surgical oncologist(外科肿瘤学家) and director of the Froedtert she cancelled her appointment to get a second opinion elsewhere. Ultimately, Joyce's cancer required a mastectomy(乳房切除术). Reconstructive surgery took place right away. She came to think of Dr. Walker as her partner, "not just my doctor. "And the Froedtert nurses, she says, were "very unusual and impressive. " As it turned out, Joyce would soon have the chance to do something important for her sister Mary Ellen. During her own cancer treatment, Joyce suggested that Mary Ellen should get herself checked through the Froedtert & Medical College of Wisconsin Breast Cancer Program. In addition to its opportunities for examination and screening, the hospital had established a program especially for women in families at high risk for cancer. Sure enough, it turned out that Mary Ellen had some cysts(囊肿) ,one of which was dangerous enough that it needed to be surgically removed. She's fine now--thanks to Joyce's suggestion. Both sisters experienced firsthand how Froedtert & Medical College of Wisconsin offers more than leading-edge technology and the unmatched experience of physicians in an academic medical center. It offers a comprehensive team approach-of consultation, collaboration, and care-all focused on the individual patient. That's why Joyce came to think of Froedtert, throughout the process of her treatment, as being her "security blanket". Joyce Sipes has been cancer-free five years now-an important milestone (里程碑)for breast cancer survivors. Joyce and Mary Ellen are together once again in their workshop in Joyce's home, making the beautiful market baskets, bread baskets, muffin(松饼) baskets, and Nantucket baskets that they--and their customers--love.

单选题His idea to solve the problem is really original .

单选题My doctor said I should vary my diet more.

单选题The Race into Space American millionaire Dennis Tito will always be famous. He was the first tourist in space. "I spent sixty years on Earth and eight days in space and from my viewpoint, it was two separate lives," Tito explained. He loved his time in space. "Being in space and looking back at earth is one of the most rewarding experiences a human being can have." This kind of experience isn"t cheap. It cost $ 20 million. However, Tito achieved his dream, so he was happy. "For me it was a life dream. It was a dream that began when I didn"t have any money," he told reporters. On April 30, 2002, Mark Shuttleworth became the world"s second space tourist. Shuttleworth is a South African businessman. At the age of twenty-eight, he also paid $20 million for the eight-day trip. Both Tito and Shuttleworth bought their tickets from a company called Space Adventures. The company has around 100 people already on their waiting list for flights into space. The spaceship to take them doesn"t exist yet. Many of the customers are persons who like adventure. They are the kind of people who also want to climb Mount Qomolangma. Other customers are people who love space. However, these people are worried. Because it"s so expensive, only very rich people can go into space. They want space travel to be available to more people. That day may soon be here. Inter Orbital Systems (IOS) plans to send up to four tourists a week into space. The tours will depart from an island in Tonga. The company promises a package that includes forty-five days of astronaut training in Russia and California, seven days in space, and a vacation in Tonga, for $2 million. However, space flight is still very dangerous. Bill Readdy is NASA"s deputy assistant administrator for space flight. He says that the chances of dying are about 1 in 500. Because of this it may take time before space tourism really takes off. You might be able to go up, but will you come down?

单选题The manager allocates duties to the clerks.

单选题He looked {{U}}dismayed{{/U}} when he heard the news.