雅思真题听力场景精练 第68期:科技类讲座 生物与化学(5)
日期:2013-08-02 16:40

(单词翻译:单击)

In Australia, where people spend a lot of time at the beach, the governmnet has realized that it must prevent sharks from swimming near its beaches. As a result, they’ve introduced a beach-netting program. Beach-netting, or meshing, involves setting large nets parallel to the shore; this means that the nets on New South Wales beaches are set on one day, and then lifted and taken out to sea on the next day. When shark-netting first began in 1939, only the Sydney metropolitan beaches were meshed——these beaches were chosen because beaches near the city are usually the most crowded with swimmers. Ten years later, in 1949, systematic meshing was extended to include the beaches to the south of Sydney. As a result of the general success of the program in Sydney, shark-meshing was introduced to the state of Queensland around 1970. The New Zealand authorities also looked at it, but considered meshing uneconomical——as did Tahiti in the Pacific. At around the same time, South Africa introduced meshing to some of its most popular swimming beaches.

When meshing began, approximatal fifteen hundred sharks were caught in the first year. However, this declined in the years that followed, and since that time, the average annual catch has been only about a hundred and fifty a year. The majority of sharks are caught during the warmest months, from November to February, when sharks are most active and when both the air and the ocean are at their maximum termperature.

Despite quite large catches, some people believe that shark meshing is not the best way to catch sharks. It’s not that they think sharks are afraid of nets, or because they eat holes in them, because neither of these is true. But meshing does appear to be less effective than some other methods, especially when there are big seas with high rolling waves and strong currents and anything that lets the sand move—the sand that’s holding the nets down. When this moves the nets will also become less effective.

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重点单词
  • majorityn. 多数,大多数,多数党,多数派 n. 法定年龄
  • pacificn. 太平洋 adj. 太平洋的 pacific adj
  • settingn. 安装,放置,周围,环境,(为诗等谱写的)乐曲 动词
  • metropolitann. 大都市的居民,大主教 adj. 大都市的,大主教区
  • popularadj. 流行的,大众的,通俗的,受欢迎的
  • systematicadj. 有系统的,分类的,体系的
  • preventv. 预防,防止
  • effectiveadj. 有效的,有影响的
  • sharkn. 鲨鱼 n. 贪婪的人,放高利贷的人,老手 v. 诈
  • extendedadj. 延续的,广大的,扩大范围的 动词extend的