单选题This passage can be most likely to be entitled

单选题 The exploitation of the power in the Sun's rays is a form of alternative energy now showing new commercial promise. In the US, manufacturers have made important{{U}} (26) {{/U}}in the development of the technology to bring down the cost of solar conversion systems{{U}} (27) {{/U}}improving their reliability. The direct conversion of solar{{U}} (28) {{/U}}electrical energy, using photovoltaic cells{{U}} (29) {{/U}}distinct advantages as an alternative energy option. {{U}} (30) {{/U}}other forms of renewable energy, photovoltaic is based on modular solid state devices which can be mass{{U}} (31) {{/U}}at a relatively low cost. Here wafers of silicon—not dissimilar{{U}} (32) {{/U}}ones which are turned into silicon chips—{{U}} (33) {{/U}}an electric current when light falls upon them. When built into panels or modules where each cell interconnects, the amount of electricity generated can be large enough to{{U}} (34) {{/U}}a home or even a community. Over the past 10 years, {{U}}(35) {{/U}}extensive research and substantial Government and private industry funding, the price of photovoltaic modules has dropped{{U}} (36) {{/U}}. {{U}} (37) {{/U}}in 1973-74 the price per peak watt was between US $100 and $150, commercial prices for small array system now vary between $6.50 and $7 per watt. This rapid price reduction has been accompanied by a 400 per cent jump in the{{U}} (38) {{/U}}efficiency of photovoltaic modules. {{U}} (39) {{/U}}solar cells are poor converters of sunlight to electricity. Early cells could only manage to mm about five per cent of the incident rays into electricity, but recent development have increased{{U}} (40) {{/U}}to more than 10 percent.

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单选题 Questions 14 to 17 are based on the following passage. At the end of the passage, you will be given 20 seconds to answer the questions. Now, listen to the passage.

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单选题Jack is so ______ to his appearance that he never has his clothes pressed.[A] adverse[B] hostile[C] indifferent[D] casual

单选题Questions 21 to 23 are based on the following news. At the end of the news item, you will be given 15 seconds to answer the questions. Now, listen to the news.

单选题I instantly enlarged on the danger of delay, putting all the considerations before her in every ______ form. [A] imagined [B] imaginary [C] imaginative [D] imaginable

单选题Which is the topic sentence of the passage?

单选题When will doctors be flown in from other hospitals?

单选题The famous basketball player of American ______ chose to play for the country in which he had won the citizenship.A. bentB. descentC. descendantD. region

单选题What does "For all you say, I think she"s the best teacher we"ve got." mean?

单选题The thief tried to break away from the police who ______ him, but failed.

单选题The evolution of sex ratio has produced, in most plants and animals with separate sexes, approximately equal numbers of males and females. Why should this be so? Two main kinds of answers have been offered. One is couched in terms of advantage to population. It is argued that the sex ratio will evolve so as to maximize the number of meetings between individuals of the opposite sex. This is essentially a "group selection" argument. The other, and in my view correct, type of answer was first put forward by Fisher in 1930. This "genetic" argument starts from the assumption that genes can influence the relative numbers of male and female offspring produced by an individual carrying the genes. That sex ratio will be favored which maximizes the number of descendants an individual will have and hence the number of gene copies transmitted. Suppose that the population consisted mostly of females, and then an individual who produced sons only would have more grandchildren. In contrast, if the population consisted mostly of males, it would pay to have daughters. If, however, the population consisted of equal numbers of males and females, sons and daughters would be equally valuable. Thus a one-to-one sex ratio is the only stable ratio; it is an "evolutionarily stable strategy". Although Fisher wrote before the mathematical theory of games had been developed, his theory incorporated the essential feature of a game that the best strategy to adopt depends on what others are doing. Since Fisher"s time, it has been realized that genes can sometimes influence the chromosome or gamete in which they find themselves so that the gamete will be more likely to participate in fertilization. If such a gene occurs on a sex-determining (X or Y) chromosome, then highly aberrant sex ratios can occur. But more immediately relevant to game theory are the sex ratios in certain parasitic wasp species that have a large excess of females. In these species, fertilized eggs develop into females and unfertilized eggs into males. A female stores sperm and can determine the sex of each egg she lays by fertilizing it or leaving it unfertilized. By Fisher"s argument, it should still pay a female to produce equal numbers of sons and daughters. Hamilton, noting that the eggs develop within their host—the larva of another insect—and that the newly emerged adult wasps mate immediately and disperse, offered a remarkably cogent analysis. Since only one female usually eggs in a given larva, it would pay her to produce one male only, because this one could fertilize all his sisters on emergence. Like Fisher, Hamilton looked for an evolutionarily stable strategy, but he went a step further in recognizing that he was looking strategy.

单选题Ever since the Puritans named their babies Fly-Fornication, America has been a land of naming freedom and self-expression. While other governments impose restrictions—German parents have to choose a name that clearly indicates the gender of the child and is not a surname, and the French, among others, forbid names that might expose a child to mockery—in the United States, anything goes. In 1950, nearly 30 percent of all babies were given one of the top ten names, a proportion that's now shrunk to less than 10 percent. Popular baby names today include locales like Brooklyn and London; surnames as given names that summon images of Waspy dynasties, such as Morgan and Whitney; and brand names of upscale products. A century ago, immigrants often changed their names as a first step toward assimilation, with Bridgets morphing into Bettys and Giovannis naming their sons plain John. Now parents are going back to their ethnic roots for inspiration. With assimilation no longer the issue, the classic Italian name Giovanni is close to being in the top 100 names for boys, and Gianna has already made it into the top 100 names for girls. Giving your child an ethnically distinct name can be a double-edged sword. "I grew up hating my name," says Orly Telisman, 35, named for her grandfather Orrin. But in college, she discovered an unexpected advantage Orly comes from the Hebrew word for light. "Explaining my name gave me a way to say, I'm Jewish, which culturally and spiritually means a lot to me," she says. "To appreciate my name, I had to grow into my own skin. " The search for a name that screams " I'm unique!" leads some parents to invent names or play with traditional spelling. Besides the classic Irish Aidan in the Social Security list of top 1,000 names, for example, there are also Aiden, Ayden, Aden, Adan, Aaden, Aydan, and Aedan. Sometimes bucking the latest trends means choosing something that others might see as decidedly out of style. Lee Krasny, 34, named her now-two, year-old daughter Dorothy, after the girl's maternal great- grandmother. "We struggled for a long time with whether to name her Dorothy or just use the D and select a modern-sounding name, but it seemed most authentic to go straight up. " A downside of a "creative" name is that it may come with baggage, not all of it positive. "I always felt I was prejudged by my name," says Gestin Skaggs, 43, whose parents named her for a word they heard in a German love song. "I've either had to overcome some stereotype of a short, fat German man or live up to an expectation that I'm a really wild and creative thinker.② People ascribe all kinds of personality traits to me that I don't have. " But that's a small price to pay, say the teens with offbeat names we spoke with. "I've met a lot of people because of my name. They hear it and think it's cool," says Calypso Gibaldi, 15, named by her ocean-loving father for Jacques Cousteau's boat. "If my name was Jane, I'd be average like everyone else. /

单选题A Dream of Red Chamber is said ______ into several languages in the last decade.

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单选题The chief anxiety northerners felt was that_______.