单选题 Geothermal (地热的) energy has been used for thousands of years in some countries for cooking and heating. It is simply power derived from the Earth's internal heat. This thermal energy is contained in the rock and fluids beneath Earth's crust. It can be found from shallow ground to several miles below the surface, and even farther down to the extremely hot molten rock called magma (岩浆). A geothermal heat pump system can take advantage of the constant temperature of the upper ten feet (three meters) of the Earth's surface to heat a home in the winter while extracting heat from the building and transferring it back to the relatively cooler ground in the summer. Geothermal water from deeper in the Earth can be used directly for heating homes and offices, or for growing plants in greenhouses. Some US cities pipe geothermal hot water under roads and sidewalks to melt snow. To produce geothermal-generated electricity, well, sometimes a mile (1.6 kilometers) deep or more, are drilled into underground reservoirs to tap steam and very hot water that drive turbines linked to electricity generators. The first geothermally generated electricity was produced in Larderello, Italy, in 1904. There are three types of geothermal power plants: dry steam, flash, and binary (二元介质式). Dry steam, the oldest geothermal technology, takes steam out of fractures in the ground and uses it to directly drive a turbine. Flash plants pull deep, high-pressure hot water into cooler, low-pressure water. The steam that results from this process is used to drive the turbine. In binary plants, the hot water is passed by a secondary fluid with a much lower boiling point than water. This causes the secondary fluid to turn to vapor, which then drives a turbine. Most geothermal power plants in the future will be binary plants. There are many advantages of geothermal energy. It can be extracted without burning a fossil fuel such as coal, gas, or oil. Geothermal fields produce only about one-sixth of the carbon dioxide that a relatively clean natural-gas-fueled power plant produces. Unlike solar and wind energy, geothermal energy is always available, 365 days a year. It's also relatively inexpensive; savings from direct use can be as much as 80 percent over fossil fuels. But it has some environmental problems. The main concern is the release of hydrogen sulfide (硫化氢), a gas that smells like rotten eggs at low concentrations. Another concern is the disposal of some geothermal fluids, which may contain low levels of toxic materials. Although geothermal sites are capable of providing heat for many decades, eventually specific locations may cool down.

单选题My friend's son, who is a soldier, was delighted when he was ____ only a few miles from home.

单选题Cultural exchange plays an important role_______promoting relation between the twocountries. 

单选题I don"t believe him. He ______ be serious.

单选题Jean: Hello, Wilson, this is Jean. Listen, Wilson... Ted: ______

单选题The population of China is ______ than ______ of any other country in the world. A. larger, the one B. more, that C. larger, that D. more, the one

单选题下面的短文后列出了10个句子，请根据短文的内容对每个句子作出判断：如果该句提供的是正确信息，选择A；如果该句提供的是错误信息，选择B；如果该句的信息文中没有提及，选择C。在答题卡相应位置上将答案选项涂黑。Setting Effective Goals　　Avital Schweitzer, 17, is clearly goal directed.She works hard to achieve

单选题So far as the food industry is concerned, the processing of sheep and lambs is relatively ______ in the United States, accounting for only about 7 percent of meat-packing production.

单选题 Yesterday Mary offered to help me to learn Japanese ______.

单选题Assuming that a constant travel-time budget, geographic constraints and short-term infrastructure constraints persist as fundamental features of global mobility, what long-term results can one expect7 In high-income regions, (41) North America, our picture suggests that the share of traffic (42) sup plied by buses and automobiles will decline as high-speed transport rises sharply. In developing countries, we (43) the strongest increase to be in the shares first for buses and later for automobiles. Glob ally, these (44) in bus and automobile transport are partially offsetting. In all regions, the share of low-speed rail transport will probably continue its strongly (45) decline. We expect that throughout the period 1990—2050, the (46) North American will continue to de vote most of his or her 1. 1-hour travel-time (47) to automobile travel. The very large demand (48) air travel (or high-speed rail travel) that will be manifest in 2050 (49) to only 12 minutes per person a day; a little time goes a long way in the air. In several developing regions, most travel (50) in 2050 will still be devoted to nonmotorized modes. Buses will persist (51) the primary form of motorized transportation in developing countries for decades. (52) important air travel becomes, buses, automobiles and (53) low-speed trains will surely go on serving vital functions. (54) of the super-rich al ready commute and shop in aircraft, but average people will continue to spend most of their travel time on the (55) .

单选题The trumpet player was certainly loud. But I wasn"t bothered by his loudness ______ by his lack of talent.

单选题The everyday life of a policeman or detective is ______.

单选题Waste paper and glasses could be ______ while most plastic could not.

单选题根据下面资料，回答问题。When I was at school， our teacher told the class "You are what you eat. " My friends and I would laugh and call each other "hamburger"（汉堡） and "biscuits". Our teacher was trying to show us

单选题It is commonly believed that in the United States school is where people get an education. Nevertheless, it has been said that today children interrupt their education to go to school. The 42 between schooling and education implied by this remark is important. Education is much more open-ended and all-inclusive than schooling. Education has no 43 . It can take place anywhere, whether in the shower or on the job, whether in a kitchen or on a tractor. It includes both the 44 learning that takes place in school and the whole universe of informal leaning. The agents of education can 45 from a revered grandparent to the people debating politics on the radio, from a child to a distinguished scientist. Whereas schooling has a certain predictability, education quite often produces surprises. A(n). 46 conversation with stranger may lead a person to discover how little is known of other religions. People are 47 in education from infancy on. Education, then, is a very broad, inclusive term. It is a lifelong process, a process that starts long before the start of school and one that should be an integral part of one's entire life. Schooling, on the other hand, is a specific, 48 process, whose general pattern varies little from one setting to the next. Throughout a country, children arrive at school at 49 the same time, take assigned seats, use similar textbooks, take exams, and so on. The slices of reality that are to be learned, whether they are the alphabet or an understanding of the workings of governments, have usually been limited by the boundaries of the 50 being taught. For example, high-school students know that they are not likely to 51 out in their classes the truth about political problems in their communities or what the newest filmmakers are experimenting with. A．formalized B．accurately C．figure D．stretch E．engaged F．similarity G．subject H．automatic I．chance J．range K．distinction L．divisional M．approximately N．bounds O．formal

单选题Concern over the economic situation was ______ in the government budget.

单选题There are millions of left-handed.people in the world.A number of them got together in1975 to form an association called Left-handers International.The purpose of the organization is to fight discrimi

单选题Mr. Li is the present ______ of the presidential chair of the company.

单选题The environmental balance among ecological communities is Uexceedingly/U complex.

单选题In spring and summer, the most popular ______ is tennis. A. work B. activity C. games D. sport