共用题干Keeping Cut Flowers（鲜切花）1. While everybody enjoys fresh cut flowers around his/her 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 lon-ger when kept at 12℃than when kept at 26℃．Keeping freshly harvested flowers at the right tem-peratures 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 at-tract birds or insects,such as bees,for pollination（授粉）.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 color. 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 respi-ration controlled?By controlling temperature .We know that respiration produces heat,but the re-verse（相反的过程）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（漂白剂）can be used in small quantities.It is recommended that 15 drops of chlorine bleach(at 4%solution)be add-ed to each litre of water. The water and solution should also be replaced each day. Respiration plays a key role________.A: by keeping its original shape and colorB: in the life of cut flowersC: to produce carbon dioxideD: for as long as possibleE: by controlling temperatureF: to replace the water and solution every day
共用题干
Keeping Cut Flowers（鲜切花）
1. While everybody enjoys fresh cut flowers around his/her 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 lon-ger when kept at 12℃than when kept at 26℃．Keeping freshly harvested flowers at the right tem-peratures 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 at-tract birds or insects,such as bees,for pollination（授粉）.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 color. 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 respi-ration controlled?By controlling temperature .We know that respiration produces heat,but the re-verse（相反的过程）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（漂白剂）can be used in small quantities.It is recommended that 15 drops of chlorine bleach(at 4%solution)be add-ed to each litre of water. The water and solution should also be replaced each day.
Keeping Cut Flowers（鲜切花）
1. While everybody enjoys fresh cut flowers around his/her 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 lon-ger when kept at 12℃than when kept at 26℃．Keeping freshly harvested flowers at the right tem-peratures 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 at-tract birds or insects,such as bees,for pollination（授粉）.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 color. 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 respi-ration controlled?By controlling temperature .We know that respiration produces heat,but the re-verse（相反的过程）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（漂白剂）can be used in small quantities.It is recommended that 15 drops of chlorine bleach(at 4%solution)be add-ed to each litre of water. The water and solution should also be replaced each day.
Respiration plays a key role________.
A: by keeping its original shape and color
B: in the life of cut flowers
C: to produce carbon dioxide
D: for as long as possible
E: by controlling temperature
F: to replace the water and solution every day
A: by keeping its original shape and color
B: in the life of cut flowers
C: to produce carbon dioxide
D: for as long as possible
E: by controlling temperature
F: to replace the water and solution every day
参考解析
解析：本段的第一句和最后一句都是该段的主题句，但是最后一句是此题的答案，选项D 几乎是最后一句的原句重现，故选D。
本段几乎都是在介绍呼吸的作用，从语篇中我们可以看到呼吸在花朵形成及死亡的过程中的作用以及它对种子和能量的形成中的作用，选项C符合题意，故选C。
本题的题设具有迷惑性，选项A和选项F都是与“花朵的呼吸”有关，但是选项A 是说如何控制呼吸，而选项F是说如何停止呼吸，回到原文，我们发现作者并没有提到停止呼吸，只是说要通过降低温度来控制呼吸，故选A。
本段第一句是该段的主题句，该段阐述了花朵护养中的另外一个重要因素——干净水的重要性。选项E符合题意，故选E。
本题的答案在第一段，该段的最后一句话中的第一个词this是关键词，要回答该题，我们只需把这个this所代指的意思找到，从上下文可以看出，它代指了前一句中的How to keep them for as long as possible。选项D符合题意，故选D。
本题其实与上面第24题意思相似，都是在说呼吸的作用。通过对24题的分析，我们知道呼吸在花朵一生中起到重要作用，选项B符合题意，故选B。
本题的答案可以在第四段的最后一句中找到，把选项E填入空格中，该题几乎是第四段的最后一句的完整重现，故选E。
本题较简单，只要找到全文的最后一句就能正确回答该题，选项F符合题意，故选F。
本段几乎都是在介绍呼吸的作用，从语篇中我们可以看到呼吸在花朵形成及死亡的过程中的作用以及它对种子和能量的形成中的作用，选项C符合题意，故选C。
本题的题设具有迷惑性，选项A和选项F都是与“花朵的呼吸”有关，但是选项A 是说如何控制呼吸，而选项F是说如何停止呼吸，回到原文，我们发现作者并没有提到停止呼吸，只是说要通过降低温度来控制呼吸，故选A。
本段第一句是该段的主题句，该段阐述了花朵护养中的另外一个重要因素——干净水的重要性。选项E符合题意，故选E。
本题的答案在第一段，该段的最后一句话中的第一个词this是关键词，要回答该题，我们只需把这个this所代指的意思找到，从上下文可以看出，它代指了前一句中的How to keep them for as long as possible。选项D符合题意，故选D。
本题其实与上面第24题意思相似，都是在说呼吸的作用。通过对24题的分析，我们知道呼吸在花朵一生中起到重要作用，选项B符合题意，故选B。
本题的答案可以在第四段的最后一句中找到，把选项E填入空格中，该题几乎是第四段的最后一句的完整重现，故选E。
本题较简单，只要找到全文的最后一句就能正确回答该题，选项F符合题意，故选F。