久久一区二区三区精品-久久一区二区明星换脸-久久一区二区精品-久久一区不卡中文字幕-91精品国产爱久久久久久-91精品国产福利尤物免费

四級沖刺練習閱讀132

雕龍文庫 分享 時間: 收藏本文

四級沖刺練習閱讀132

  Although given less publicity, the agricultural damage done by the many smaller, more frequent floods usually far exceeds the losses caused by the very grand ones. In the Central States, ditches and drains cause the flows from spring rains and melting snow to run far more rapidly than in the days before white men settled on the land. Once, excess spring flood waters emptied into lakes and swampy lands, there to be detained for slow release into stream and rivers. Now, systematic drainage has actually eliminated these natural reservoirs.

  In the more rolling sections of the East, spring runoff was formerly absorbed and held temporarily in the porous soils beneath the unbroken expanse of forest. When large areas were converted to farm use, removal of the forest and the practice of up-and-down hill plowing deprived the soils of much of their ability to catch and store water.

  The effects of eliminating the natural forest cover are shown in the gullied farm lands and widened stream channels found in some densely settled areas. Partly because the stream channels are more or less filled with material washed down from the uplands, and partly because storm runoff has increased, the channels are today no longer able to carry all the flow from heavy rains. This explains why the streams overtop banks far more often than in the days before settlement.

  26. The best title for the selection would be______.

  A. River Rising! River Rising! B. Forests and Floods

  C. Flooding in the U. S. D. The Results of Flooding

  27. All of the following cause floods EXCEPT______.

  A. heavy rain B. melting snow

  C. increasing storm runoff D. porous soil

  28. The author states that______.

  A. lakes and swamps once acted like natural reservoirs

  B. up-and-down hill plowing catches and stores water

  C. stream channels are the best carriers of water

  D. floods are easily prevented and controlled

  29. According to the selection, streams overtop their banks partly because______.

  A. material from higher land is washed into them

  B. ditches and drains lead into them

  C. rivers become too swift

  D. snow melts more rapidly nowadays

  30. The floods which are given most publicity______.

  A. cause no damage

  B. cause the most damage

  C. cause less agricultural damage than the many smaller, more frequent floods

  D. far exceed the smaller, more frequent floods in agricultural loss

  26. C 27. D 28. A 29. A 30. C

  

  Although given less publicity, the agricultural damage done by the many smaller, more frequent floods usually far exceeds the losses caused by the very grand ones. In the Central States, ditches and drains cause the flows from spring rains and melting snow to run far more rapidly than in the days before white men settled on the land. Once, excess spring flood waters emptied into lakes and swampy lands, there to be detained for slow release into stream and rivers. Now, systematic drainage has actually eliminated these natural reservoirs.

  In the more rolling sections of the East, spring runoff was formerly absorbed and held temporarily in the porous soils beneath the unbroken expanse of forest. When large areas were converted to farm use, removal of the forest and the practice of up-and-down hill plowing deprived the soils of much of their ability to catch and store water.

  The effects of eliminating the natural forest cover are shown in the gullied farm lands and widened stream channels found in some densely settled areas. Partly because the stream channels are more or less filled with material washed down from the uplands, and partly because storm runoff has increased, the channels are today no longer able to carry all the flow from heavy rains. This explains why the streams overtop banks far more often than in the days before settlement.

  26. The best title for the selection would be______.

  A. River Rising! River Rising! B. Forests and Floods

  C. Flooding in the U. S. D. The Results of Flooding

  27. All of the following cause floods EXCEPT______.

  A. heavy rain B. melting snow

  C. increasing storm runoff D. porous soil

  28. The author states that______.

  A. lakes and swamps once acted like natural reservoirs

  B. up-and-down hill plowing catches and stores water

  C. stream channels are the best carriers of water

  D. floods are easily prevented and controlled

  29. According to the selection, streams overtop their banks partly because______.

  A. material from higher land is washed into them

  B. ditches and drains lead into them

  C. rivers become too swift

  D. snow melts more rapidly nowadays

  30. The floods which are given most publicity______.

  A. cause no damage

  B. cause the most damage

  C. cause less agricultural damage than the many smaller, more frequent floods

  D. far exceed the smaller, more frequent floods in agricultural loss

  26. C 27. D 28. A 29. A 30. C

  

主站蜘蛛池模板: 综合欧美日韩一区二区三区 | 精品国产乱码久久久久久一区二区 | 一区二区三区国模大胆 | 国产精品视频免费观看调教网 | 欧美一区二区三区视频在线 | 国产精品亚洲欧美日韩区 | 亚洲欧美日韩在线一区二区三区 | 一级特黄国产高清毛片97看片 | 玖草在线观看 | 久久久久久久久久久福利观看 | 另类专区 亚洲 | 国内精品1区1区3区4区 | 日本强不卡在线观看 | 亚洲精品区在线播放一区二区 | 欧美一级淫片免费观看 | a理论片 | 一区二区三区免费在线视频 | 特级做a爰片毛片免费看一区 | 美女曰皮 | 福利片成人午夜在线 | 九九视频在线观看视频 | 中文字幕乱码无线码在线 | 国产91会所洗浴女技师按摩 | 99久久精品免费看国产免费 | 精品韩国主播福利视频在线观看一 | 亚洲欧美日韩精品久久亚洲区 | 农村寡妇一级毛片免费播放 | 久久影院在线 | 亚洲欧美激情视频 | 一级毛片欧美大片 | 一级毛片真人不卡免费播 | 久精品在线观看 | 国产三级在线播放线 | 国产综合第一页 | 欧美精品免费线视频观看视频 | 亚洲一区欧美 | 狠狠色噜噜狠狠狠米奇9999 | 欧美综合自拍亚洲综合百度 | 国产成人一区二区视频在线观看 | 黄a网站| 国产成人一区二区三中文 |