Question

15．Two-thirds of the world's major rivers have now been disrupted（中斷）with more than 50，000 dams in an attempt to stole water and provide power．In the US，there are more than 85，000 dams，disrupting large and small rives，and in most cases transforming natural flow．The most famous of these，the Hoover Dam，constructed in the l930's，is mainly responsible for the fact that the Colorado River no longer reaches the ocean．
    Dams，besides all their attractive benefits，also have negative impacts．Creating a reservoir means a large area must be flooded．Communities may lose their land，houses and culturally impotent sites．
    Environmentally，the new reservoir can be a paradise for wildlife，especially birds．However，it can cause greenhouse gas emissions（排放）and poison the water for fish．Also，the dramatic rise and fall of water levels during dam releases is too extreme for plains and animals to cope with，resulting in dead zones around the shores of reservoirs．Fish that lay their eggs in the shallows，for example，may find a few hours later that those sites are high and dry．
    Dams don't just block water flow．They also prevent fish migrations，and are a barrier to sediment （沉淀物）flows．Instead of rushing downriver，sediments get backed up against the dam wall，which cause the reservoir level to increase over time．However，sediments which are rich in nutrients have become a problem．The fertility of the entire system can be influenced，with soils lost during seasonal rains not being replaced．
     Perhaps the biggest problem can be seen in deltas（三角洲），often host to large cities，which are sinking into the oceans．Groundwater is being extracted to feed the city，causing the urban weight to sink and sediments washed away by the ocean are no longer being replaced．The result is that sea level rise in cities from Shanghai to Alexandria．
51．What effects does creating a reservoir have on people's life？D
  a．People will see fewer birds near the rivers．
  b．Farmers below the dam may have less water to irrigate their fields
  c．Visitors can't see some cultural relics anymore．
  d．More conflicts and wars over water will break out
  e．More kinds of fish will become extinct in the future
  A．a(chǎn)，c    B．c，e    C．b，e   D．b，c
52．With many dams built across rivers，fish willB
  A．find more places to lay their eggs    B．face a more dangerous living habitat
  C．feed on more sediment rich in nutrients D．find it easier to deal with the rise of water
53．How can dams influence the cities like Shanghai？C
  A．Its entire system will be influenced．    B．The rainy season will last longer．
  C．It will lie below sea level in the future   D．Rich soils will be washed away
54．What does the text mainly talk about？A
  A．Environmental loss of dams．B．Cultural loss of dams
  C．Economical gain of dams      D．Environmental benefits of dams
55．Where can we most probably read this passage？C
    A．In a travel magazine     B．In a personal diary
    C．In a science report       D．In a biology textbook．

Answer 1

分析 本文屬于說(shuō)明文閱讀，作者通過(guò)這篇文章主要向我們描述的是人類在世界各地修建的大壩對(duì)環(huán)境造成的影響．它不僅淹沒(méi)了一些文化遺跡，還導(dǎo)致下游的農(nóng)民無(wú)法灌溉農(nóng)作物，更使得三角洲的一些大城市面臨被海水淹沒(méi)的危險(xiǎn)，因此對(duì)于大壩的建造一定要謹(jǐn)慎，不要因一時(shí)的利益造成更大的損失．

解答 51．D．細(xì)節(jié)理解題．根據(jù)文章第二段"Communities may lose their land，houses and culturally impotent sites"和第四段"The fertility of the entire system can be influenced，with soils lost during seasonal rains not being replaced"可知，隨著大壩的修建，蓄水淹沒(méi)了一些文化遺跡，還導(dǎo)致下游的農(nóng)民無(wú)法灌溉農(nóng)作物，故選D．
52．B．推理判斷題．根據(jù)文章第三段中的"it can cause greenhouse gas emissions and poison the water"可知，隨著大壩的修建，蓄水會(huì)釋放出溫室氣體，使水有毒，所以魚的生活環(huán)境會(huì)變得危險(xiǎn)，故選B．
53．C．細(xì)節(jié)理解題．根據(jù)文章最后一段中的"Perhaps the biggest problem can be seen in deltas（三角洲），often host to large cities，which are sinking into the oceans"可知，三角洲中的大型城市可能會(huì)被海水淹沒(méi)，上海正屬于位于三角洲的大型城市，因此很可能被海水淹沒(méi)，故選C．
54．A．主旨大意題．通讀全文可知，本文主要講的是修建大壩對(duì)環(huán)境造成的影響，它淹沒(méi)了一些文化遺跡，還導(dǎo)致下游的農(nóng)民無(wú)法灌溉農(nóng)作物，更使得三角洲的一些大城市面臨淹沒(méi)的危險(xiǎn)，可知主旨為大壩對(duì)環(huán)境的危害；故選A．
55．C．推理判斷題．通讀全文可知本文主要講的是修建大壩對(duì)環(huán)境造成的影響，給出了實(shí)例充分說(shuō)明了這個(gè)觀點(diǎn)，語(yǔ)言十分嚴(yán)謹(jǐn)，可推出這是一份科學(xué)報(bào)告；故選C．

點(diǎn)評(píng) 考察學(xué)生的細(xì)節(jié)理解和推理判斷能力，做細(xì)節(jié)理解題時(shí)一定要找到文章中的原句，和題干進(jìn)行比較，再做出正確的選擇．在做推理判斷題不要以個(gè)人的主觀想象代替文章的事實(shí)，要根據(jù)文章事實(shí)進(jìn)行合乎邏輯的推理判斷．