单选题The atmosphere consists of _________.

单选题Jack is a {{U}}diligent{{/U}} student. A. ambitious B. hardworking C. lazy D. slow

单选题Poor health and lack of money may both be roadblocks to educational progress.

单选题The tower remains {{U}}intact{{/U}} ever after two hundred years. A. unknown B. unusual C. undamaged D. unstable

单选题Which of the following is true of the sand-buried landscape?

单选题The student has checked his test paper thoroughly.A. seldomB. quicklyC. completelyD. roughly

单选题下面有3篇短文，每篇短文后有5道题，每题后面有4个选项。请仔细阅读短文并根据短文回答其后面的问题。{{B}}第一篇{{/B}} Electric Backpack Backpacks are convenient. They can hold your books, your lunch, and a change of clothes, leaving your hands free to do other things. Someday, if you don't mind carrying a heavy load, your backpacks might also power your MP3 player, keep your cell phone' running, and maybe even light your way home. Lawrence C. Rome and his colleagues from the University of Pennsylvania in Philadelphia and the Marine Biological Laboratory in Woods Hole, Mass. , have invented a backpack that makes electricity from energy produced while its wearer walks. In military actions, search-and-rescue operations, and scientific field studies, people rely increasingly on cell phones, global positioning system (GPS) receivers, night-vision goggles, and other battery-powered devices to get around and do their work. The backpack's electricity-generating feature could dramatically reduce the amount of a wearer's load now devoted to spare batteries, report Rome and his colleagues in the Sept. 9 Science. The backpack's electricity-crew, ring powers depend on springs used to hang a cloth pack from its metal frame. The frame sits against the wearer's back, and the whole pack moves up and down as the person walks. A gear mechanism converts vertical movements of the pack to rotary motions of an electrical generator, producing up to 7.4 watts. Unexpectedly, tests showed that wearers of the new backpack alter their gaits in response to the pack's oscillations, so that they carry loads more comfortably and with less effort than they do ordinary backpacks. Because of that surprising advantage, Rome plans to commercialize both electric and non-electric versions of the backpack. The backpack could be especially useful for soldiers, scientists, mountaineers, and emergency workers who typically carry heavy backpacks. For the rest of us, power-generating backpacks could make it possible to walk, play video games, watch TV, and listen to music, all at the same time. Electricity-generating packs aren't on the market yet, but if you do get one eventually, just make sure to look both ways before crossing the street!

单选题George is very proud of his new Ustatus/U in the company.

单选题I am feeling a lot more healthy than I was.

单选题Since ancient times people have found various ways to preserve meat. A．eat B．cook C．freeze D．keep

单选题The fuel tanks had a capacity of 140 liters.

单选题Can you lend me some dollars? I just lack cash. A. short B. need C. waste D. arrange

单选题下面的短文有15处空白，请根据短文内容为每处空白确定1个最佳选项。 China to help Europe Develop GPS Rival China is to contribute to a new global satellite navigation system being developed by European nations. The Galileo satellite system {{U}}(51) {{/U}} a more accurate civilian alternative to the Global Positioning System(GPS), operated by the US military. China will provided 230m Euros (USD 259m) in {{U}}(52) {{/U}} and will cooperate with technical, manufacturing and market development. "China will help Galileo to {{U}}(53) {{/U}} the major world infrastructure for the growing market for location services, " said Loyola de Palacio, EU transport commissioner. A new center that will coordinate co-operation was also announced {{U}}(54) {{/U}}) the European Commission, the European Space Agency (ESA) and the Chinese Ministry of Science and Technology not long {{U}}(55) {{/U}}. The China-Europe Global Navigation Satellite System Technical Training and Cooperation Center will be {{U}}(56) {{/U}} at Beijing University. China has a substantial satellite launch industry and could potentially help the Galileo satellites. The US has claimed that Galileo could interfere {{U}}(57) {{/U}} the US ability to downgrade the GPS service during military conflicts. European officials say this is unfounded and counter that US opposition {{U}}(58) {{/U}} the commercial challenge Galileo would present to GPS. Galileo will be precise to within a meter, while civilian GPS service is accurate to around 10 meters. The Galileo satellite constellation will {{U}}(59) {{/U}} 27 operational and three reserve satellites orbiting the Earth at an altitude of 23,600 km. The satellites will be strung along three medium-Earth orbits at 56 degrees inclination to the equator and will provide global coverage. The system should be operational by 2008 and the entire project is expected to {{U}}(60) {{/U}} around 3.2 billion Euros(USD 3.6 billion). The European Commission has said Galileo will primarily be used for transportation technology, scientific research, land management and disaster monitoring. Galileo will provide two signals: a standard civilian one and an encrypted, wide-band signal {{U}}(61) {{/U}} the Public Regulated Service (PRS). This second signal is designed to withstand localized jamming and will be used by police and military services in Europe. European Commission {{U}}(62) {{/U}} have said China will not be given access to the PRS. The first Galileo satellite is scheduled to launch late in 2004, Clocks on board the {{U}}(63) {{/U}} Will be synchronized through 20 ground sensors stations, two command centers and 15 uplink stations. Receivers on the ground will use time signals from the satellites to precisely calculate their {{U}}(64) {{/U}}. A "search and rescue" function will also {{U}}(65) {{/U}} distress signals be relayed through the constellation of satellites.

单选题She Ustarted/U to clean the kitchen.

单选题The first A3XX will be available in 2003.

单选题There should be laws that {{U}}prohibit{{/U}} smoking around children. A. advocate B. forbid C. inherit D. withdraw

单选题High-Tech Warfare (战争) Today, high-tech warfare is no longer an abstract concept, but a real issue. Technology (1) tactics, sociology, and the development of weaponry (武器). It also causes the changes in battles. Then what are the new characteristics of modern battles (2) by the application of high technologies? High-tech warfare naturally includes high technology. In modern battles, a single kind of weapon can hardly be (3) . Various weaponry, such as intelligence detection and information processing, should (4) well with each other. Aerial (航空的) weaponry becomes the main force in battles in the sky. Precision homing (精确制导) weaponry like cruise missiles and missiles (5) satellite homing systems becomes the main attack weapons. Battle control systems play a dominant role. Various weapons and logistics (后勤) systems are (6) into a comprehensive framework, centrally representing the modern high-tech weaponry. Depending on various (7) equipment and means in electronic warfare, our army will not be passively beaten. (8) the battlefield, high-tech warfare has created a type of non-linear (非线性的) chaos. Because of the use of long-range precision weaponry, the opposite parties in warfare can't "touch" or "see" each other, and distance is no longer the decisive factor affecting the (9) of battles. It is hard to clearly define the lines between the frontier and the rear, as well as attack and defense. The traditional three-dimensional air-sea battlefield will be (10) by the multi-dimensional battlefield composed of air, sea, magnetic, electrical and information battlefields. No large-scale movements can be conducted (11) . Because modern weaponry systems are closely related to chains of demand and communication and electronic technology, the parties (12) have to pay attention to the usufruct (使用权) and control of electromagnetic frequency spectrum. So electronic warfare becomes (13) important and the necessary guarantee of victory. Whatever (14) warfare goes to and whatever cloak (宽大外衣) it wears, it always violates peace and brings the world bloodshed (流血). Most people think of high technology as a (15) to enhance their lives, and they don't wish it to be used to destroy lives.

单选题John is collaborating with Mary in writing an article.

单选题When required by their parents to eat green vegetables, many children only do so Ureluctantly/U.

单选题I have no alternative but to report him to the local police.