根据短文内容, 从下框A~F选项中选出能概括每段主题的最佳选项，并在答题卡上将该选项涂黑。选项中有一项为多余项。A. Control of respirationB. Basi

根据短文内容, 从下框A~F选项中选出能概括每段主题的最佳选项，并在答题卡上将该选项涂黑。选项中有一项为多余项。
A. Control of respiration
B. Basic tips for preserving cut flowers
C. Role of respiration
D. Most important aspect of flower care
E. Need for clean water
F. Ways of stopping respiration

【小题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. The key to keeping fresh cut flower for a week or more without preservatives ( which contain biocides (杀虫剂) that kill bacterial and fungus) is to keep the water fresh and the stems free of air pockets so they can continue to draw up water.
【小题2】
An important thing to remember about cut flowers is that they are sensitive to temperature. For example, studies have shown that cut carnations retain their freshness eight times longer when kept at 12℃ than when kept at 26℃. Keeping freshly harvested flowered at the right temperatures is probably the most important aspect of flower care.
【小题3】
The process by which flowers consume oxygen and produce carbon dioxide, called respiration (呼吸), supplies 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.
【小题4】
How, then, to control the speed at which flowers die? By controlling respiration. How is respiration controlled? By controlling temperature, we know that respiration produces heat, but the reverse ( 反面 ) is also true. Thus by keeping low temperatures, respiration is reduced and the cut flower will age more slowly.
【小题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, chlorine bleach ( 含氯漂白剂 ) can be used in small quantities. It is recommended that 15 drops of chlorine bleach be added to each liter of water. The water and solution （ 溶液 ）should also be replaced each day.B

(答案→)B 解析：文章介绍如何护理保护修剪下来的花的建议，要在适当的温度修剪花，控制花的呼吸，还有用清洁的水等。【小题1】考查段落大意题：从这段的句子：While everybody enjoys fresh cut flowers around his house, few people know how to keep them for as long as possible.可知这段讲的是：保护修剪下来的花的建议：答案是：B【小题2】考查段落大意题：从这段的句子：Keeping freshly harvested flowered at the right temperatures is probably the most important aspect of flower care.可知这段讲的是：花卉护理的重要方法，答案是：D【小题3】考查段落大意题：从这段的句子：The process by which flowers consume oxygen and produce carbon dioxide, called respiration (呼吸), supplies the energy the flower needs to give the flower its shape and color.可知这段讲的是：呼吸的重要性，答案是：C【小题4】考查段落大意题：从这段的句子：How, then, to control the speed at which flowers die? By controlling respiration.可知这段讲的是：怎么控制呼吸，答案是：A【小题5】考查段落大意题：从这段的句子：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.可知这段讲的是：对清洁的水的需求，答案是：E

我明天再问问老师，叫他解释下这个问题