单选题Nelson is a creative liar who is always making __________ unusual excuses for not doing his work.

单选题Will you mind ______ him now ______ the next stop?

单选题What is the proper title for this passage?

单选题City officials are considering building a path to give the public ______ to the site. [A] recreation [B] excess [C] excursion [D] access

单选题Rain is not what it used to be. A new study reveals that much of the precipitation in Europe contains such high levels of dissolved pesticides that it could be illegal to supply it as drinking water. Studies in Switzerland have found that rain is laced with toxic levels of atrazine, alachlor and other commonly used crop sprays. "Drinking water standards are regularly exceeded in rain," says Stephan Muller, a chemist at the Swiss Federal Institute for Environmental Science and Technology in Dubendorf. The chemicals appear to have evaporated from fields and become part of the clouds. Both the European Union and Switzerland have set a limit of 100 nanograms for any particular pesticide in a liter of drinking water. But, especially in the first minutes of a heavy storm, rain can contain much more than that. In a study to be published by Muller and his colleague Thomas Bucheli in Analytical Chemistry this summer, one sample of rainwater contained almost 4000 nanograms per liter of 2, 4-dinitrophenol, a widely used pesticide. Previously, the authors had shown that in rain samples taken from 41 storms, nine contained more than 100 nanograms of atrazine per liter, one of them around 900 nanograms. In the latest study, the highest concentrations of pesticides turned up in the first rain after a long dry spell, particularly when local fields had recently been sprayed. Until now, scientists had assumed that the pesticides only infiltrated groundwater directly from fields. Muller warns that the growing practice of using rainwater that falls onto roofs to recharge under — ground water may be adding to the danger. This water often contains dissolved herbicides that had been added to roofing materials, such as bitumen sheets, to prevent vegetation growing. He suggests that the first flush of rain should be diverted into sewers to minimize the pollution of drinking water, which is not usually treated to remove these herbicides and pesticides.

单选题Scientists have spent years into the effects of certain chemicals on the human brain, but with no result. A. studying B. researching C. investigating D. inspecting

单选题The headquarters of this textile company is in New York while its 20______. companies are located in different parts of the world. A. parent B. subsidiary C. inferior D. ultimate

单选题The type of job an ape could do without supervision would be one which is ______.

单选题Lily: Have you lost weight? Mary:______

单选题The main point of paragraph 5 is ______.

单选题What conclusion can be drawn from the essay about the United States during the time of Henry Ford's youth?

单选题This ad will be very helpful to______.

单选题She felt a bit ______ in the autumn air so she went in to fetch a coat.

单选题Each plant and animal by natural tendency, ______ far more seeds and eggs and seedlings and young, than is necessary to maintain ______ population.

单选题The children were having a wonderful time ______ on the frozen lake. A. slipping B. slithering C. skidding D. sliding

单选题It is no ______ that his car was seen near the bank at the time of the robbery.

单选题His major task is to integrate the work of various bureaus under the ministry.

单选题 Volcanoes are the ultimate earth-moving machinery. Eruptions have rifted continents, raised mountain chains, constructed islands and shaped the topography of the earth. The entire ocean floor has a basement of volcanic basalt. Volcanoes have not only made the continents, they are also thought to have made the world's first stable atmosphere and provided all the water for the oceans, rivers and ice-caps. There are now about 600 active volcanoes. Every year they add two or three cubic kilometers of rock to the continents. Imagine a similar number of volcanoes smoking away for the last 3,500 million years. That is enough rock to explain the continental crust. What comes out of volcanic craters is mostly gas. More than 90% of this gas is water vapor from the deep earth: enough to explain, over 3,500 million years, the water in the oceans. The rest of the gas is nitrogen, carbon dioxide, sulphur dioxide, methane, ammonia and hydrogen. The quantity of these gases, again multiplied over 3,500 million years, is enough to explain the mass of the world's atmosphere. We are alive because volcanoes provided the soil, air and water we need. Geologists consider the earth as having a molten core, surrounded by a semi-molten mantle and a brittle, outer skin. It helps to think of a soft-boiled egg with a runny yolk, a firm but squishy white and a hard shell. If the shell is even slightly cracked during boiling, the white material bubbles out and sets like a tiny mountain chain over the crack—like an archipelago of volcanic islands such as the Hawaiian Islands. But the earth is so much bigger and the mantle below is so much hotter. Even though the mantle rocks are kept solid by overlying pressure, they can still slowly 'flow' like thick treacle. The flow, thought to be in the form of convection currents, is powerful enough to fracture the 'eggshell' of the crust into plates, and keep them bumping and grinding against each other, or even overlapping, at the rate of a few centimeters a year. These fracture zones, where the collisions occur, are where earthquakes happen. And, very often, volcanoes.

单选题I learned to ______a bicycle as a small boy.