单选题Her claims seem credible to many people.

单选题He denies involvement with either drugs or the CIA.

单选题Jane said that she couldn't {{U}}tolerate{{/U}} the long hours. A. stand B. spend C. take D. last

单选题There is a small risk of brain damage from such an operation.

单选题She felt that she had done her good deed for the day.

单选题People don't realize how serious this recession has actually been.A. knowB. thinkC. doubtD. remember

单选题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 (51) a more accurate civilian alternative to the Global Positioning System (GPS), operated by the US military, China will provide 230m Euros (USD 259m) in (52) and will cooperate with technical, manufacturing and market development. "China will help Galileo to (53) 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 (54) the European Commission, the European Space Agency (ESA and the Chinese Ministry of Science and Technology not long (55) . The China-Europe Global Navigation Satellite System Technical Training and Cooperation Center will be (56) at Beijing University. China has a substantial satellite launch industry and could potentially help launch the Galileo satellites. The US has claimed that Galileo could interfere (57) the US ability to downgrade the GPS service during military conflicts. European officials say this is unfounded and counter that US opposition (58) the commercial challenge Galileo would present to GPS. Galileo will be precise to within meter, while the civilian GPS service is accurate to around 10 meters. The Galileo satellite constellation will (59) 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 (60) 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 (61) 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 (62) 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 (63) 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 (64) . A "search and rescue" function will also (65) distress signals be relayed through the constellation of satellites.

单选题Strict sanitary procedures help to forestall out-breaks of disease.

单选题Less Is More It sounds all wrong—drilling holes in a piece of wood to make it more resistant to knocks. But it works because the energy from the blow gets distributed throughout the wood rather than focusing on one weak spot. The discovery should lead to more effective and lighter packaging materials. Carpenters have known 1 centuries that some woods are tougher than others. Hickory (山核桃木), for example, was turned into axe handles and cartwheel spokes (轮辐) because it can absorb shocks without breaking. White oak, for example, is much more easily damaged, 2 it is almost as dense. Julian Vincent at Bathe University and his team were convinced the wood"s internal structure could explain the differences. Many trees have tubular (管状的) vessels that run 3 the trunk and carry water to the leaves. In oak they are large, and arranged in narrow bands, but in hickory they are smaller, and more evenly distributed. The researchers 4 this layout might distribute a blow"s energy throughout the wood soaking up a bigger hit. To test the idea, they drilled holes 0.65 millimetres across into a block of spruce (云杉), a wood with 5 vessels, and found that 6 withstood a harder knock. 7 when there were more than about 30 holes per square centimetre did the wood"s performance drop off. A uniform substance doesn"t cope well with knocks because only a small proportion of the material is actually 8 . All the energy from the blow goes towards breaking the material in one or two places, but often the pieces left 9 are pristine (未经破坏的). But instead of the energy being concentrated in one place, the holes provide many weak spots that all absorb energy as they break, says Vincent. "You are controlling the places 10 the wood breaks, and it can then absorb more 11 , more safely." The researchers believe the principle could be applied to any material— 12 example, to manufacture lighter and more protective packaging. It could 13 be used in car bumpers, crash barriers and armour for military vehicles, says Ulrike Wegst, a 14 at the Max Plank Institute for Mental Research in Stuttgart. But she emphasizes that you 15 to design the substance with the direction of force in mind. "The direction of loading is crucial," she says.

单选题We are going to have the TV {{U}}fixed{{/U}}.

单选题The painter Les Quinones, whose graffiti art has been {{U}}exhibited{{/U}} in New York galleries, has also painted outdoor murals in various Manhattan neighborhoods.

单选题The prisoners grew increasingly desperate .

单选题Language teachers often extract examples from grammar books.

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。 {{B}} Vibrating Rubber Cellphones{{/B}} Vibrating rubber cellphones could be the next big thing in mobile communications. They allow people to press the phone to transmit vibrations along with their {{U}}(51) {{/U}} words. According to a research team at the MIT Media Lab in Cambridge, Massachusetts, the idea will make {{U}}(52) {{/U}} more fun. Many mobile phones can already vibrate instead of ringing {{U}}(53) {{/U}} you do not want people to know you are getting a call. But these {{U}}(54) {{/U}} are toe simple for subtle (敏感的) communication, {{U}}(55) {{/U}} Angela Chang of the lab's Tangible Media Group. "They're either on or off," she says. But when you hold Chang's rubber cellphone, your fingers and thumb wrap around five {{U}}(56) {{/U}} speakers. They vibrate {{U}}(57) {{/U}} your skin around 250 times per second. Beneath these speakers sit pressure sensors (传感器), so you can transmit vibration as well as {{U}}(58) {{/U}} it. When you squeeze with a finger, a vibration signal is transmitted {{U}}(59) {{/U}} your caller's corresponding finger. Its speed {{U}}(60) {{/U}} on how hard you squeeze. Chang says that within a few minutes of being given the phones,, students were using the vibration feature to {{U}}(61) {{/U}} emphasis to what they were saying. Over time, people even began to transmit their own kind of ad hoc (特别的) "Morse code", which they would repeat back to show they were {{U}}(62) {{/U}} what the other person was saying. Chang thinks "vibralanguages" could function for the same {{U}}(63) {{/U}} as texting: sometimes people want to communicate {{U}}(64) {{/U}} without everyone nearby knowing what they're saying. "And {{U}}(65) {{/U}} actually being able to shake someone's hand when you close a business deal," she says.

单选题Why do you want to throw away those books?

单选题Egypt Felled by Famine Even ancient Egypt"s mighty pyramid builders were powerless in the face of the famine that helped bring down their civilization around 2180 BC. Now evidence gleaned (搜集) from mud deposited by the River Nile suggests that a shift in climate thousands of kilometers to the south was ultimately to blame—and the same or worse could happen today. The ancient Egyptians depended on the Nile"s annual floods to irrigate their crops. But any change in climate that pushed the African monsoons (季风) southwards out of Ethiopia would have diminished these floods. Dwindling (使减少) rains in the Ethiopian highlands would have meant fewer plants to establish the soil. When rain did fall it would have washed large amounts of Soil into the Blue Nile and into Egypt, along with sediment (沉积物) from the White Nile. The Blue Nile mud has a different isotope (同位素) signature from that of the White Nile. So by analyzing isotope differences in mud deposited in the Nile Delta, Michael Krom of Leeds University worked out what proportion of sediment came from each branch of the river. Krom reasons that during periods "of drought, the amount of the Blue Nile mud in the river would be relatively high. He found that one of these periods, from 4,500 to 4,200 years ago, immediately predated the fall of the Egypt"s old Kingdom. The weakened waters would have been catastrophic for the Egyptians. "Changes that affect food supply don"t have to be very large to have a ripple effect in societies," says Bill Ryan of the Lamont Doherty Earth Observatory (天文台) in New York. "Similar events today could be even more devastating ," says team member Daniel Stanley, a geoarchaeologist from the Smithsonian Institution in Washington, D. C. "Anything humans do to shift the climate belts would have an even worse effect along the Nile system because the populations have increased dramatically."

单选题What does the president say he is doing?

单选题With Uimmense/U relief, I stopped running.

单选题Which of the following statements is true?

单选题The army should have operated Uin conjunction/U with the fleet to raid the enemy's coast.