单选题5. So quickly is technology advancing ______ is a possibility today may be a reality tomorrow.

单选题24. The signal made by the watchman could mean nothing ______ than a halt to the advance.

单选题 As Mercury moves in its solar orbit

单选题28. I think she must be a pop music lover, ______?

单选题 For him to be reelected

单选题13. ______ our most recent memo indicates is ______ we haven't yet protected ourselves against the risk of the market.

单选题23. It was not until he entered the airport ______ he realized that he had forgotten to bring his air ticket with him.

单选题. Gallaudet University currently does not allow students to keep pets in their dorm rooms 21 are made only for service animals such as guide dogs and hearing dogs. These 22 dogs provide services that benefit their student owners. But other kinds of pets can be 23 to students too. Pets should be allowed to live in the dorms because they can help students 24 stress and learn responsibility. College life is very 25 and students often feel a lot of pressure and 26 . Pets could help students relieve 27 in many ways. For example, playing with pets could give students a study break. Walking a dog or playing with a cat would allow the students to relax their body and 28 . When the students return to their studying, they would feel 29 and ready to work again. Pets could also relieve social stress or homesickness. A dog or cat could provide 30 and affection when students have problems with their friends or 31 home. Sometimes it is easier to talk to a pet than to a person. Talking about problems helps students figure out 32 . Pets would have a positive influence on the stress of college life. College is also a time when students need to learn to be responsible. 33 pets could help students learn responsibility in several ways. 34 , pets need to be fed and watered on a regular schedule. Some pets also need to be taken out 35 others need their litter box or cage cleaned. Students would learn to schedule time for these 36 between their classes and activities. New students 37 having their parents do things for them. But parents do not live 38 college campuses with their children. Therefore, caring for a pet is something students would have to do 39 . They would learn how to solve problems on their own and how to follow through with their commitments. Having pets would teach students to 40 more adult responsibilities.21.

单选题 Culture is activity of thought

单选题11. My approach is not to learn everything about something, but ______ something about everything.

单选题7. Taj Mahal in India is perhaps one of the most beautiful buildings in the world, where I spent ______ moonlit night.

单选题 Such ______ the case

单选题12. The twelve constellations located along or near the ecliptic ______ the signs of the zodiac.

单选题26. ______, the box will break into pieces.

单选题28. The development of mechanical timepieces spurred the search for more accurate sundials ______.

单选题. Synchronized Sex 性的同步 by Menno Schilthuizen When the biological clocks of males and females are out of sync, their sex lives suffer. Or at least it does if they are melon flies, Japanese entomologists have found. They say that differences in daily rhythms might even promote the evolution of new species. Takahisa Miyatake and Toru Shimizu of Okinawa Prefectural Agricultural Experimental Station made their discovery while studying the melon fly Bactrocera cucurbitae, a notorious pest of melons, couregttes and other members of the gourd family. By selective breeding from flies that were quickest to mature and mate, they built up a population of fast developing individuals. In a similar way, they also bred a line of slow developers. After 25 generations, the slow developers' larvae took more than 12 days to mature, while the fast developers matured in just 6 days. To their surprise, Miyatake and Shimizu noticed that this was not the only difference between the two lines. In nature, the melon flies mate around dusk. But among the fast developers, sexual activity peaked in late afternoon, one hour before dusk, while the slow developers only started getting interested in sex around three-and-a-half hours after nightfall. "Apparently, both rhythms are regulated by the same clock gene," says Miyatake. To see how this would influence the ability of the slow and the fast lines to crossbreed, the researchers marked flies from both lines, put them together in cages, and watched to see which mated with expected, which as most matings took place between males and females from the same line. The finding, which will be reported in the journal Evolution, suggests that differences in body clocks could cause new species to evolve. Miyatake says the behaviour of some species suggest they may have arisen this way. "Many closely related species of insect differ in their daily mating time," he says. "For example, the only thing that separates two other flies, Bactrocera tryoni and bactrocera neohumeralis, is the fact that the former mates at dusk, the latter in the daytime." "This is interesting work," says Jeffrey Feder, an evolutionary geneticist who studies fruit flies at the University of Notre Dame in Indiana. "It is very exciting that Miyatake and Shimizu have shown how selection on the larvae can affect the mating pattern in adults and prevent crossbreeding." Feder agrees that the effect could be important in the evolution of new species, especially when insects undergo a shift in lifestyle. For example, if a population of flies starts feeding on a new fruit that rots quickly, this could select for fast-developing larvae with a different mating time and which would not breed with the ancestral stock. "This is getting at the heart of what Darwin was saying in On the Origin of Species," says Feder.11. It can be inferred from the first paragraph that ______.

单选题18. The police chief announced that he would soon inquire ______ the deaths of two young girls.

单选题. The Brain and the Computer 大脑与计算机 Considering that the brain can be compared to the electronic computer, it may be useful to ask if one computer, the brain, has any advantages over the other, the electronic computer. First, compare the amount of energy needed to operate the brain and that needed to run a computer. It has been calculated that the entire brain runs on very little energy as compared with a machine. A machine with as great a capacity as the brain—assuming one could be built—would need at least one million times as much electrical power to continue operating. But the computer is a faster worker than the brain. The advanced calculators are thousands upon thousands of times faster than the brain, and models yet to be built will probably be yet speedier. Memory is of great importance in "Computer-type" operations. The number of bits of information that can be stored determines the ability of the system to do complex operations. The more bits stored, the more complex the calculations that can be made. In 1962, advanced electronic computers could store about 40,000 bits of information. Here, the brain shows its distinct advantages: although the number of bits stored is certainly not known, it has been estimated at many millions of bits. One specialist has said that to build a machine to imitate the capacity of the human brain, it would be necessary to make it the size of a very tall building. "The brain is like a computing machine, but there is no computing machine like the brain." Humans, however, may not continue to have this superiority in the future. Recent developments in electronic equipment, for example, Sceptron, have rapidly changed our ideas. Each Sceptron is extremely small, which may mean that is will soon be possible to make a calculator as complex as the human brain—with the same bit storage capacity—and be able to fit it neatly in a desk. There is one great and very important distinction between humans and machines. While electronic devices may think, "hunger" for electricity, and in other ways imitate animal and human behavior, men have desires, hungers, thirsts, and a complex existence of which the brain is a major, but not the entire, aspect. Human hopes and fears are not like those of the electronic mechanisms, nor will they be so long as we continue to construct thinking machines whose function is only to think as they are programmed. The use that man makes of automation, decision-making machines, and the other results of cybernetics is dependent on man himself. As Norbert Wiener states in his book The Human Use of Human Beings mankind is faced with two possible destructive directions in which cybernetics could develop, influencing all of society. One is that machines that do not learn will obey all instructions and never vary in their approach to problems. The other is that man may find himself in the position of someone who has released an angry force. Machines that can learn and make decisions on the basis of their learning are not obligated to decide in ways that please or improve humanity. Men cannot give machines responsibility for mankind; final choices must always be made by, and in favor of, men.1. The energy needed to operate the human brain is ______ that needed to run a computer.

单选题 We thought she'd come just for a visit

单选题 Everybody knows that the earth is spherical