文勇的新托福黄金&ccedil

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Unformatted text preview: the passage is closest in meaning to ○Far away ○Hidden ○Partly visible ○Discovered 4. According to paragraph 2, where is groundwater usually found? ○Inside pieces of sand and gravel ○On top of beds of rock ○In fast rivers that are flowing beneath the soil ○In spaces between pieces of sediment 92 Mail@liuwenyong.com 在在在在在在 www.liuwenyong.com 在在在在在在在在在在在在在在在,在在在在在在在在在在 5. The phrase “glacial outwash” in the passage refers to ○Fast rivers ○Glaciers ○The huge volumes of water created by glacial melting ○The particles carried in water from melting glaciers. Paragraph 3: The same thing happens to this day, though on a smaller scale, wherever a sediment­laden river or stream emerges from a mountain valley onto relatively flat land, dropping its load as the current slows: the water usually spreads out fanwise, depositing the sediment in the form of a smooth, fan­shaped slope. Sediments are also dropped where a river slows on entering a lake or the sea, the deposited sediments are on a lake floor or the seafloor at first, but will be located inland at some future date, when the sea level falls or the land rises; such beds are sometimes thousands of meters thick. 6. All of the following are mentioned in paragraph 3 as places that sediment­laden rivers can deposit their sediments EXCEPT ○A mountain valley ○Flat land ○A lake floor ○The seafloor Paragraph 4: In lowland country almost any spot on the ground may overlie what was once the bed of a river that has since become buried by soil; if they are now below the water’s upper surface (the water table), the gravels and sands of the former riverbed, and its sandbars, will be saturated with groundwater. 7. The word “overlie” in the passage is closest in meaning to ○Cover ○Change ○Separate ○Surround Paragraph 5: So much for unconsolidated sediments. Consolidated (or cemented) sediments, too, contain millions of minute water­holding pores. This is because the gaps among the original grains are often not totally plugged with cementing chemicals; also, parts of the original grains may become dissolved by percolating groundwater, either while consolidation is taking place or at any time afterwards. The result is that sandstone, for example, can be as porous as the loose sand from which it was formed. 8. The phrase “so much for” in the passage is closest in meaning to ○That is enough about ○Now let us turn to ○Of greater concern are ○This is related to 9. The word “plugged” in the passage is closet in meaning to ○Washed ○Dragged 93 Mail@liuwenyong.com 在在在在在在 www.liuwenyong.com 在在在在在在在在在在在在在在在,在在在在在在在在在在 ○Filled up ○Soaked through Paragraph 6: Thus a proportion of the total volume of any sediment, loose or cemented, consists of empty space. Most crystalline rocks are much more solid; a common exception is basalt, a form of solidified volcanic lava, which is sometimes full of tiny bubbles that make it very porous. Paragraph 7: The proportion of...
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