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 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

相关问题推荐

• 水分是鲜切花植物生存的重要条件，在鲜切花栽培中无论什么鲜切花都一样浇水才能长得旺盛。

  A、对

  B、错

  查看答案

• 情人节（2月14日），美国销售的鲜切玫瑰花多来自哥伦比亚。读下图回答下列问题。小题1:.与美国相比，在情人节期间，哥伦比亚生产鲜切花的优势自然条件是　（）

  A．气温较高

  B．降水较丰沛

  C．地势较平

  D．土壤较肥沃小题2:.美国的农业生产实现了地区生产的专业化，形成了一些农业带（区），图中①处是　（）

  A．小麦区

  B．乳畜带

  C．玉米带

  D．棉花带

  查看答案

• 下图示意的甲、乙两国分别为传统、新兴的鲜切花生产国。据此，回答1—2题。

  

  1、比较甲、乙两国降水特点及其原因  ①甲国受西风带和暖流影响，全年降水较丰沛且季节分配均匀  ②甲国受副热带高压带和西风带的交替影响，降水季节差异大  ③乙国受赤道低压带影响，全年降水丰沛且季节分配均匀  ④乙国受地形影响，降水季节差异大

  [  ]

  A、①③B、①④C、②③D、②④

  2、与甲国相比，乙国发展鲜切花生产的优势自然条件是  ①热量丰富②光照充足③地形平坦④水源丰富

  [  ]

  A、①②B、①④C、②③D、③④

  查看答案

• 阅读图文材料，完成下列问题。（19分)材料1：2012年9月19日上午，2012中国昆明国际花卉展暨2012第八届昆明冷亚国际农业博览会，在昆明国际会展中心隆重开幕。材料2：“云南区域轮廓图”。材料3：昆明和荷兰花卉生产各项条件的贡献率（%)

  指标

  气候等自然条件

  劳动力

  冷藏保鲜

  机械化科技

  鲜切花水平及广告等

  昆明

  50

  30

  10

  5

  5

  荷兰

  40

  5

  20

  20

  15（1)从地理位置、地形因素分析云南省的主要气候特征。（6分)

  （2)结合材料和所学知识，分析昆明发展花卉生产的有利条件。（8分)（3)根据材料3，分析促进昆明花卉生产的措施。（5分)

  查看答案
• 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.
  A few simple facts will help you keep cut flowers________.
  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

  查看答案