(单词翻译:单击)
听力文本
From VOA Learning English, this is the Agriculture Report.
Irrigation systems can make a big difference in agricultural production. Irrigation can also improve the lives of farm families. However, the addition of water to the land or soil may cause problems in some areas. A new study describes how irrigation water can lead to an increase in malaria cases that could last for ten years or more.
Malaria is spread by mosquitoes, the insects like to reproduce in standing water. So when a dry area is irrigated, the disease can appear and spread.
Mercedes Pascual is a scientist at the University of Michigan. She and her team studied areas in northern India where irrigation systems were built over a number of years. They compared how malaria progressed with the spread of irrigation.
"What happens is that when you irrigate, there is more, in a sense, more breeding habitats for the mosquito."
She and the other scientist found that after farmers began irrigating their crops, the risk of malaria rose sharply. At first, her team thought maybe the number of cases rose because there was little effort to control the mosquitoes that spread the disease. But they were wrong.
"In fact, we saw the opposite. This transition stage was characterized not just by heightened malaria risk, but also by more intervention to control the mosquito vector."
Even after the mosquito control efforts were in place, the researchers found high rates of malaria continued for ten years or longer.
Mercedes Pascual suggests that the irrigation project supervisors need to work more on reducing places where mosquitoes might reproduce. She also says health officials may need to try other methods of malaria prevention that would work for long periods of time.
"And what we are saying is that those measures have to be sustained, and sustained and also planned for, for the long term."
In the words of the researchers, irrigation offers considerable rewards in areas with low rainfall. But as Mrs Pscual and her team discovered irrigation also can bring years of high rates of malaria. The only way to avoid the problem is through better planning and control measures.
A report on the study was published in the Proceedings of the National Academy of Sciences of the United States of America.
And that's the Agriculture Report from VOA Learning English. You can download transcripts and MP3s of all of our programs at our website, voaspecialenglish.com. You can also find captioned videos at the VOA Learning English channel on YouTube. I'm Christopher Cruise.
译文属可可原创，仅供学习交流使用，未经许可请勿转载
词汇解释
1.irrigation n. 灌溉；[临床] 冲洗；冲洗法
Irrigation is needed to make crops grow in dry regions.
干旱地区需要灌溉才能使作物生长。
2.habitat n. [生态] 栖息地，产地
Many species are in peril of extinction because of our destruction of their natural habitat.
许多物种由于我们破坏了它们的自然环境， 现在正面临灭绝的危险。
3.vector n. 矢量；带菌者；航线
Neither vector nor reservoir has been discovered and proved.
媒介和贮主至今都没曾得到发现和证实。
4.reproduce vt. 复制；再生；生殖；使…在脑海中重现 vi. 复制；繁殖
Most plants reproduce through seeds.
多数植物都是靠种子来繁殖。
内容解析
1.Irrigation systems can make a big difference in agricultural production.
make a big difference 产生很大的不同；意义重大；有很大影响
My belief in God has made a big difference in my life.
我的信仰使我生命有极大改变。
Your help has made a big difference - I understand the work better now.
你给予的帮助起了大作用 - -我现在对工作比较熟悉了。
2.In fact, we saw the opposite. This transition stage was characterized not just by heightened malaria risk, but also by more intervention to control the mosquito vector.
characterized by 以...为特征
His work is characterized by lack of attention to detail.
他的工作的特点是不注意细节。
Mozart's music is characterized by its naivety and clarity.
莫扎特的音乐特色是纯朴兴清澈。
参考译文
这里是美国之音慢速英语农业报道。
灌溉系统能在很大程度上促进农业生产，灌溉还能改善农民家庭的生活。然而在有的地区，流到田地的水流中的附加物会造成问题。一项新研究表明，灌溉用水能导致疟疾病例增加，且能持续10年甚至更久。
疟疾通过蚊子传播，这种虫子喜欢在静水中繁殖。所以当干燥的地区得到灌溉时，疾病就会出现并得以传播。
默西迪丝·帕斯奎尔是密歇根大学一名科学家，她和她的团队研究了印度北部一些地区，这里的灌溉系统是多年前建成的。他们对比疟疾如何随着灌溉的推广一同蔓延。
“事实上，灌溉会产生更多适合蚊子繁殖的栖息地。”
她和其他科学家发现，在农民开始给作物灌溉后，疟疾的风险就急剧上升。最初，她的团队以为病例之所以增加，是因为控制传播疾病蚊虫的力度不够。但他们错了。
“事实上，我们看的正好相反。这个过渡阶段的特点不仅是疟疾风险加剧，而且也进行了更多干预手段来控制蚊虫媒介。”
即使是在实施蚊虫控制后，研究者发现在10年甚至更久的时间内疟疾的风险仍很高。
默西迪丝·帕斯奎尔建议灌溉系统监督人需要做更多工作以减少蚊虫可能繁殖的区域，她说，卫生官员可能还需尝试其他可以持续长期的疟疾预防措施。
“我们想说的是，必须坚持实施这些措施，并进行未来的长期规划。”
用研究者的话来说，灌溉系统给降雨少的地区带来了可观的回报。但正如帕斯奎尔女士和她的团队发现的那样，灌溉也带了多年的疟疾高发率，避免这一问题的唯一办法就是通过更好的规划和措施实施。
有关研究报告发表在美国国家科学院院报上。
这就是本期的美国之音慢速英语农业报道，你可登陆voaspecialenglish.com下载节目的文本、音频，还可在YouTube的美国之音慢速英语频道上获取视频，我是克里斯多夫·克鲁斯。
