2. 外语
  3. Keeping Cut Flowers 1. While everybody enjoys fresh cut flowers around his house, few people know how to keep them for as long a

Keeping Cut Flowers 1. While everybody enjoys fresh cut flowers around his house, few people know how to keep them for as long a

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问题                           Keeping Cut Flowers
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℃ than when kept at 26℃. 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). 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. Then how 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(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 (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 liter of water. The water and solution should also be replaced each day.
A. Control of Respiration
B. Beauty of Fresh Cut Flowers
C. Role of Respiration
D. Most Important Aspect of Flower Care
E. Need for Clean Water
F. Ways of Stopping Respiration
Paragraph 2______
选项
答案D
解析 本题考查的是对所读材料大意与主旨的掌握。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。
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本试题收录于： 职称英语理工类C级题库职称英语分类
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