根据材料，回答问题。KeepingCutFlower（1）.Whileeverybodyenjoysfreshcutflowersaroundhish

共享题干题根据材料，回答问题。Keeping Cut Flower（1）. While everybody enjoys fresh cut flowers around his house, few people know how to keep them for as long as possible. This may be done by keeping in mind a few simple facts.（2）. An important thing to remember about cut flowers is that they are sensitive to temperature. For example, studies have shown that cut carnations (康乃馨) retain their freshness eight, times longer when kept at 12~C than when kept at 26~ C. Keeping freshly harvested flowers at the right temperatures is probably the most important aspect of flower care.（3）. Flowers are not intended by nature to live very long. Their biological purpose is simply to attract birds or insects, Such as bees, for pollination (授粉)fg). After that, they quickly dry up and die. The process by which flowers consume oxygen and produce carbon dioxide (二氧化碳), called respiration (呼吸), generates the energy the flower needs to give the flower its shape and colour. The making of seeds also depends on this energy. While all living things respire, flowers have a high level of respiration. A result of all this respiration is heat, and for flowers the level of heat relative to the mass of the flower is very high. Respiration also brings about the eventual death of the flower. Thus the greater the level of respiration, the sooner the flower dies.（4）. How, then, to control the rate at which flowers die? By controlling respiration. How is respiration controlled? By controlling temperature we know that respiration produces heat, but the reverse is also true. Thus by maintaining low temperatures, respiration is reduced and the cut flower will age more slowly.（5）. Another vital factor in keeping cut flowers is the quality of the water in which they are placed. Flowers find it difficult to "drink" water that is dirty or otherwise polluted. Even when water looks and smells clean, it almost certainly contains harmful substances that can endanger the flowers. To rid the water of these unwanted substances, household chlorine bleach (含氯漂白剂) can be used in small quantities. It is recommended that 15 drops of chlorine bleach ( at 4% solution) be added to each litre of water. The water and solution should also be replaced each day.1.[不定向选择题]Paragraph 4___A.Control of Respiration B.Beauty of Fresh Cut Flower C.Role of Respiration D.Most Important Aspect of Flower CareE.Need for Clean WaterF.Ways of Stopping RespirationABCDEF确定 2.[不定向选择题]Another important way to prolong the life of cut flowers is____A.by keeping its original shape and colour B.in the life of the cut flower C.to produce carbon dioxide D.for as long as possibleE.by controlling temperatureF.to replace the water and solution every dayABCDEF确定

1.参考答案：A
参考解析：题干：第四段的段落大意为____。?第四段的段落主题句为第二句，因为首句是个问句，问句的答案才是主题所在，即“通过控制呼吸来控制花死去的速度”，所以答案为A(控制呼吸)反映了该段的主题，因而为正确答案。?
2.参考答案：F
参考解析：题干：另外一个延长插瓶花生命的重要方式就是____。?利用题干关键词self-confidence可以定位到第五段“Another vital factor in keeping cut flowers is the quality of the water in which they are placed…The water and solution should also be replaced each day．”，即“另外一个保持插瓶花的因素就是它们所放置的水的质量……每天要更换水和溶液”，所以F(每天更换水和溶液)为正确答案。3.[不定向选择题]A few simple facts will help you keep cut flowers____A.by keeping its original shape and colour B.in the life of the cut flower C.to produce carbon dioxide D.for as long as possibleE.by controlling temperatureF.to replace the water and solution every dayABCDEF确定

和我的回答一样，看来我也对了