单选题What makes a mayor successful in Los Angeles is the Ustrength/U of his public support.

单选题If I made a mistake, I will try to {{U}}remedy{{/U}} it. A. clarify B. diagnose C. evaporate D. correct

单选题Every country represented in the Olympics has a National Olympic Committee that selects the athletes who compete in the games.

单选题Careful {{U}}consideration{{/U}} should be given to issues of health and safety. A. thought B. mind C. account D. memory

单选题They always mock me because I am ugly.

单选题Gypsies When school was out, I hurried to find my sister and get out of the schoolyard before seeing anybody in my class. But Barbara and her friends had beaten us to the playground entrance and they seemed to be waiting for us. Barbara said, "So now you're in the A class. " She sounded impressed. "What's the A class?" I asked. Everybody made superior yet faintly envious giggling sounds. "Well, why did you think the teacher moved you to the front of the room, dopey? Didn't you know you were in the C class before, way in the back of the room?" Of course I hadn't known. The Wenatchee fifth grade was bigger than my whole school which had been in North Dakota, and the idea of subdivisions within a grade had never occurred to me. The subdividing for the first marking period had been done before I came to the school, and 1 had never, in the six weeks I'd been there, talked to anyone long enough to find out about the A, B, and C classes. I still could not understand why that had made such a difference to Barbara and her friends. I didn't yet know that it was shameful and dirty to be a transient laborer and ridiculous to be from North Dakota. I thought living in a tent was more fun than living in a house. I didn't know that we were gypsies, really (how that thought would have excited me then!), and that we were regarded with the suspicion felt by those who plant toward those who do not plant. It didn't occur to me that we were all looked upon as one more of the untrustworthy natural phenomena, drifting here and there like mists or winds. I didn't know that I was the only child who had camped on the Baumann's land ever to get out of the C class. I didn't know that school administrators and civic leaders held conferences to talk about the problem of transient laborers. I only knew that for two happy days I walked to school with Barbara and her friends, played hopscotch and jumped rope with them at class intervals, and was even invited into the house for some ginger ale—a strange drink I had never tasted before.

单选题To slow down eye damage，people with diabetes should try to

单选题He still did well at school ______ taking a part - time jobs now and then.A. in spite ofB. regardingC. on account ofD. in case of

单选题The history of cancer research has shown that

单选题His idea to solve the problem is really original.A. creativeB. greatC. practicalD. perfect

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 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 southwards out of Ethiopia would have diminished these floods. Dwindling rains in the Ethiopian highlands would have meant fewer plants to stablize the soil. When rain did fall it would have washed large amounts of soil into the Blue Nile and into Egypt, along with sediment from the White Nile. The Blue Nile mud has a different isotope 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 predates 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 Doberty Earth Observatory 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 today because the populations have increased dramatically. /

单选题A lot of ants are always invading my kitchen. They are a thorough {{U}}pain in the neck{{/U}}.

单选题I have been trying to quit smoking.

单选题I felt Uimpelled /Uto tell the truth.

单选题Because of the strong sun Mrs. William new blue dining-room {{U}}curtains{{/U}} faded to gray within a year.

单选题We will take your recent illness into consideration when marking your exams.

单选题I can no longer tolerate his actions. A. put up with B. accept C. take D. suffer from

单选题A nurse is not qualified if she does not have patience and show concern for her patients.

单选题Light Night, Dark Stars Thousands of people around the globe step outside to gaze at their night sky. On a clear night, with no clouds, moonlight, or artificial lights to block the view, people can see more than 14,000 stars in the sky, says Dennis Ward, an astronomer with the University Corporation for Atmospheric Research (UCAR) in Boulder, Colo. But when people are surrounded by city lights, he says, they"re lucky to see 150 stars. If you"ve ever driven toward a big city at night and seen its glow from a great distance, you"ve witnessed light pollution. It occurs when light from streetlights, office buildings, signs, and other sources streams into space and illuminates the night sky. This haze of light makes many stars invisible to people on Earth. Even at night, big cities like New York glow from light pollution, making stargazing difficult. Dust and particles of pollution from factories and industries worsen the effects of light pollution. "If one city has a lot more light pollution than another," Ward says, "that city will suffer the effects of light pollution on a much greater scale." Hazy skies also make it far more difficult for astronomers to do their jobs. Cities are getting larger. Suburbs are growing in once dark, rural areas. Light from all this new development is increasingly obscuring the faint light given off by distant stars. And if scientists can"t locate these objects, they can"t learn more about them. Light pollution doesn"t only affect star visibility. It can harm wildlife too. It"s clear that artificial light can attract animals, making them go off course. There"s increasing evidence, for example, that migrating birds use sunsets and sunrises to help find their way, says Sydney Gauthreaux Jr., a scientist at Clemson University in South Carolina. "When light occurs at night," he says, "it has a very disruptive influence." Sometimes birds fly into lighted towers, high-rises, and cables from radio and television towers. Experts estimate that millions of birds die this way every year.

单选题Listening Device Provides Landslide Early Warning A device that provides early warning of a landslide by monitoring vibrations in soil is being tested by UK researchers. Tile device could save thousands of lives each year by warning when an area should be evacuated, the scientists say. Such natural disasters are common in countries that experience sudden, heavy rainfall, and can also be triggered by earthquakes and even water erosion. Landslides start when a few particles of soil or rock within a slope start to move,but the early stages can be hard to spot. Following this initial movement, "slopes can become, unstable in a matter of hours or minutes," says Nell Dixon at Loughborough University, UK. He says a warning system that monitors this movement "might be enough to evacuate a block of fiats or clear a road, and save lives." The most common way to monitor a slope for signs of an imminent landslide is to watch for changes in its shape. Surveyors can do this by measuring a site directly, or sensors sunk into boreholes or fixed above ground can be used to monitor the shape of a slope. Slopes can, however, change shape without triggering a landslide, so either method is prone to causing false alarms. Now Dixon"s team has developed a device that listens for the vibrations caused when particles begin moving within a slope. The device takes the form of a steel pipe dropped into a borehole in a slope. The borehole is filled in with gravel around the pipe to help transmit high-frequency vibrations generated by particles within the slope. These vibrations pass up the tube and are picked up by a sensor on the surface. Software analyses the vibration signal to determine whether a landslide may be imminent. The device is currently being tested in a 6-metre-tall artificial clay embankment in Newcastle, UK. Early results suggest it should provide fewer false positives than existing systems. Once it has been carefully and thoroughly tested, the device could be used to create a complete early-warning system for dangerous slopes. "Locations with a significant risk of landslides could definitely benefit from a machine like this," says Adam Poulter, an expert at the British Red Cross. "As long as it doesn"t cost too much." But, Poulter adds that an early-warning system may not be enough on its own. "You need to have the human communication," he says. "Making systems that get warnings to those who need them can be difficult."