问题 问答题 简答题

分析干悬浮剂发展快的原因及在我国发展前景?

答案

参考答案:

干悬浮剂=水分散粒剂,入水后,自动崩解,分散成悬浮液

特点:

(1)与可湿性粉剂和悬浮剂一样,悬浮性、分散性、稳定性好

(2)与可湿性粉剂比,具有好的流动性,易于从容器中取出

(3)与悬浮剂比,可克服贮藏期间沉积结块、低温结冻

(4)再悬浮性好,配好的药液当天没用完,第二天经搅拌能重新悬浮起来,不影响应用

(5)不含有机溶剂,对环境污染小

(6)解决了乳油的经皮毒性,对作业者安全

(7)无粉尘污染,对作业者安全

(8)有效成分含量高,计量、运输、贮存方便

(9)成本比可湿性粉剂和悬浮剂高是农药剂型今后发展的一个重要方向

阅读理解

Life on earth depends on water, and there is no substitute for it. The current assumption is that our basic needs for water—whether for drinking, agriculture, industry or the raising of fish—will always have to be met. Given this premise (前提), there are two basic routes we can go; more equal access to water or better engineering solutions.

Look at the engineering solutions first. A lot of my research concentrates on what happens to wetlands when you build dams in river basins, particularly in Africa. The ecology of such areas is almost entirely driven by the seasonal changes of the river—the pulse of the water. And the fact is that if you build a dam, you generally spoil the downstream ecology. In the past, such problems have been hidden by a lack of information. But in the near future, governments will have no excuses for their ignorance.

The engineers’ ability to control water flows has created new kinds of unpredictability, too. Dams in Africa have meant fewer fish, less grazing and less floodplain (洪泛区) agriculture, none of which were expected. And there average economic life is assumed to be thirty years. Dams don’t exist forever, but what will replace them is not clear.

The challenge for the future is to find new means of controlling water. Although GM technology(转基因) will allow us to breed better dry-land crops, there is no market for companies to develop crops suitable for the micro-climates of the Sahel and elsewhere in Africa. Who is going to pay for research on locally appropriate crops in the Third World?

小题1:What’s the main idea of this passage?

A.The engineering solutions to water resource and their limitation.

B.The challenge for the future.

C.The basic means of controlling water.

D.The challenge for developing crops.小题2:The author suggests that governments will have no excuse for their careless ignorance in the future because _____.

A.The ecological destruction will be known to the public by researchers

B.The ecological destruction will no longer be a problem in the future

C.The future is an information age

D.Governments will face greater challenge in the future小题3:Which of the following statements is NOT true for meeting our basic needs for water?

A.Water resource should be used more reasonably.

B.More dams should be built in river basins.

C.More wetlands should be protected from destruction.

D.More dry-land crops could be developed in Africa.小题4:The last sentence probably implies that _____.

A.No one will invest in developing locally appropriate crops in Africa

B.Researchers have no interest in developing dry-land crops

C.Research on locally appropriate crops in the Third World may be profitable

D.There is less water resource in the Third World

填空题