sectioniireadinginteraction

sectioniireadinginteraction内容摘要：

4 The world’s population continues to expand. If action isn’t taken, as many as 7 million people in 60 countries could face water shortage by 2050. So what needs to be done? In large part, the answer lies in the development and largescale application of relatively simple technologies. Alternative solutions such as solarpowered desalination plants are very useful, particularly in wealthy west Asian countries. However, two biggest ponents of the global water shortage are the pollution of drinking supplies with human waste, and the huge waste of water in some agricultural practices. Both of these problems could be relieved by improving existing technologies. 4 5 6 11 Intensive Study Para. 5 The world’s environmental situation might be eased if we carefully deal with our waste. In the rich North, toilets using water are the largest single drain on domestic water supplies. Nevertheless, it is not a must for the developing countries that currently lack adequate capital to imitate this wasteful practice, which would require heavy investment in wastewater treatment. They need toilets which can safely turn human waste into a smellless, soillike substance. Para. 6 Meanwhile, water used for agriculture accounts for more than two thirds of human’s normal use of water. However, almost 60 percent of the water is lost during the irrigation. We do not need to be so wasteful today. By using “microirrigation”, in which water is piped and fed onto crops through sealed systems, irrigation can be made 90 percent efficient. 7 8 9 12 Intensive Study Much greater use could al。