ABCD请按实际情况填写。其他请参照下表填写。

A, B, C, D, E(AB), F(AC)

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

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 flowers for a week or more without floral preservatives(which contain biocides that kill bacteria and fungus) is to keep the water fresh and the stems free of air pockets so they can continue to draw up water.

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, 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.

 

C

  The villagers of Yaluma in Southern Mexico are some of the poorest people in the country. But now they have an extra source of income.They are being paid to grow and develop forests by the organization in charge of Formula One racing (一级方程式赛车),which pumps 5,500 tons of carbon dioxide (CO2) into the air every year.The idea is that the forests being planted around Yaluma will absorb this amount. It will also provide people there with money while wiping out motor racing's environmental debt.

  Projects like this go under the name of "carbon trading". The basic idea is that governments and companies can buy the right to pump CO2 into the air by investing in green projrvyd. They can buy so-called "carbon credits" from countries which have succeeded in reducing CO2 emissions(排放物).

  Supporters of carbon trading say that it brings money and green technology to poorer countries.It also provides a new way of doing busingess and spreading prosperity. They point out that the process of globalization will give people everywhere the most possible choice of products and services. Carbon trading is just another way of bringing that about. It is a "win - win" situation.

  Opponents argue that nature comes before lifestyle. CO2 emissions need to be reduced, not bought and sold. And they believe that the rich world should lead the way.People might be willing to change the way they live to help save the world, but not to help the rich countries keep a lifestyle that depends on pollution.

  Supporters of carbon trading believe in unlimited growth.Opponents believe that nature sets limits to the choices we make on how to live.It is "don't do " against "can do". It is life against lifestyle.

  It is believed that modern lives are about choice.For example,the world can choose to take the danger of global warming seriously.And the sooner we choose to do it, the more choices we have about what to do next and the more time we have to do it in. We can also choose to pay no attention to the danger of global warming to keep our lifestyles. Then one day nature may give us no choice at all,and maybe not much of a life,either.

  64.Carbon trading is discussed in the text in order to show the importance of ______ .

   A.reducing pollution B.taking care of forests

   C.spreading prosperity D.choosing lifestyle or nature

  65."Carbon credits" may be used to ______.

   A.get the right to pump CO2 into the air

   B.get the right to pump CO2 into poor countries

   C.learn about the way to reduce CO2 emissions

   D.improve the way to reduce CO2 emissions

  66.We can infer from the text that in the "win - win" situation _____.

   A.rich countries perform their duty to help poor countries

   B.poor countries get what they need from rich countries

   C.both rich countries and poor countries get what they need

   D.rich countries learn from poor countries in reducing pollution

  67.In the opinion of people who are against carbon trading,the rich countries should ____.

   A.guide poor countries in reducing CO2 emissions

   B.show by example how to reduce emissions

   C.offer more help to save the world

   D.improve their lifestyles to keep the world clean

 

违法和不良信息举报电话:027-86699610 举报邮箱:58377363@163.com

精英家教网