原文已被隐藏，你可用 快捷键 - 或点击 显示原文 按钮来查看原文
第一段
1 .Today we are going to look at one of my favorite fish - the shark.
今天我们要看一下我最喜欢的鱼--鲨鱼。
2 .As you know, sharks have a reputation for being very dangerous creatures capable of injuring or killing humans.
正如你所知道的，鲨鱼有着危险生物的声誉，能够伤害或杀害人类。
3 .And I'd like to talk about sharks in Australia.
我想谈论澳大利亚的鲨鱼。
第二段
1 .Sharks are rather large fish, often growing to over ten metres.
鲨鱼是相当大的鱼，通常生长到十米以上。
2 .And longest sharks caught in Australia have reached sixteen metres.
澳大利亚最长的鲨鱼达到十六米。
3 .Sharks vary in weight with size and breed, of course, but the heaviest of sharks caught in Australia was a White Pointer that weight seven hundred ninety - five kilograms - quite a size!
当然鲨鱼的大小和品种各不相同，但在澳大利亚被捕获的最重的鲨鱼是一个白色的Pointer，重达七百九十五公斤，相当大！
4 .Sharks have a different structure to most fish: instead of skeleton made of bone.
鲨鱼和大多数鱼类的结构不同:它们的骨骼不是由骨头构成的。
5 .They have a tough elastic skeleton of cartilage.
它们有坚硬的弹性软骨骨架。
6 .Unlike bone, this firm, pliable material is rather like your nose, and allows the sharks to bend easily as it swims.
与骨头不同，这种结实、柔韧的材料很像你的鼻子，让鲨鱼在游泳时很容易弯曲。
7 .The shark's skin isn't cover with scales, like other fish: instead the skin's covered with barbs, giving it a rough texture like sandpaper.
鲨鱼的皮肤不像其他鱼类那样覆盖着鳞片:相反，它的皮肤上覆盖着倒钩，使其具有砂纸一样的粗糙纹理。
8 .As you known, sharks are very quick swimmers.
如你所知，鲨鱼是非常快的游泳者。
9 .This is made possible by their fins, one set at the side and another set underneath the body.
这是由于它们的鳍，一个在侧面，另一个在身体下面。
10 .And the tail also helps the shark move forward quickly.
尾巴也帮助鲨鱼快速向前移动。
11 .Unlike other fish, sharks have to keep swimming if they want to stay at a particular depth.
与其他鱼类不同的是，如果鲨鱼想要呆在特定的深度，它们必须一直游下去。
12 .And they rarely swim at the surface.
它们很少在水面上游泳。
13 .Mostly, they swim at the bottom of ocean, scavenging and pick up food that's lying on the ocean floor.
大多数情况下，它们在海底游泳，寻找和获得海底的食物。
14 .While most other animals, including fish, hunt their prey by means of their eyesight, shark hunt essentially by smell.
大多数其他动物，包括鱼类，都是靠视力捕食，而鲨鱼主要靠嗅觉捕食。
15 .They have very acute sense of smell - and can sense the presence food long before they can see it.
它们有非常敏锐的嗅觉，在能看到食物之前就能感觉到食物的存在。
第一段
1 .In Australia where people spend a lot of time at the beach, the government have realised that it is must prevent sharks from swimming near its beaches.
在澳大利亚，人们花很多时间在海滩上，政府已经意识到必须防止鲨鱼在海滩附近游泳。
2 .As a result, they have introduced a beach - netting program, beach - netting or meshing involves setting large nets parallel to the shore.
因此，他们引进了一个海滩网计划，海滩网或网格包括设置与海岸平行的大网。
3 .This means that the nets on New South Wale beaches are set on one day.
这意味着在新南威尔海滩上的渔网是在一天内设置好的。
4 .And then lifted and taken out the sea on the next day.
第二天就举起来抛出去。
5 .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 crowed with swimmers.
当捕鲨网在1939年第一次开始使用时，只有悉尼的都市海滩才有网——之所以选择这些海滩，是因为城市附近的海滩通常是游泳者最多的。
6 .Ten years later, in 1949, systematic meshing was extended to include the beaches to the south of Sydney.
十年后的1949年，系统的网格划分扩展到包括悉尼南部的海滩。
7 .As a result of the general success of the program in Sydney.
由于悉尼项目的普遍成功。
8 .Shark - meshings was introduced to the state of Queensland around 1970.
鲨鱼网大约在1970年被引进昆士兰州。
9 .The New Zealand authorities also looked at it, but considered meshing uneconomical - as did Tahiti in the Pacific.
新西兰当局也考虑过，但认为这样做不经济——就像太平洋上的塔希提岛一样。
10 .At around the same time, South Africa introduced meshing to some of its most popular swimming beaches.
与此同时，南非将网格技术引入了一些最受欢迎的游泳海滩。
11 .When meshing began, approximately fifty hundred sharks were caught in the first year.
当网织开始时，第一年就捕获了大约五千条鲨鱼。
12 .However, this declined in the year that followed.
然而，在随后的一年里，这一数字有所下降。
13 .And since that time, the average annual catch has been only about a hundred and fifty a years.
从那时起，每年的平均捕获量只有150每年左右。
14 .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 temperature.
大多数鲨鱼都是在11月到2月这几个最热的月份被捕获的，那时鲨鱼最活跃，空气和海洋都处于它们的最高温度。
15 .Despite quite large catches, some people believe that the shark meshing is not the best way to catch sharks.
尽管捕获量相当大，一些人认为鲨鱼网不是捕捉鲨鱼的最佳方式。
16 .It's not that they think sharks are afraid of nets, or because they eat holes in them.
这并不是说他们认为鲨鱼害怕渔网, 也不是因为它们吃了网洞。
17 .Because neither of these is true.
因为这两个都不对。
18 .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 lets the sand move - the sand that's holing the nets down when this moves the nets will also become less effective.
但是，与其他一些方法相比，网孔法的效果似乎要差一些，特别是在波涛汹涌、水流湍急的大海上，任何东西都能让沙子移动的时候，尤其是当沙子把网孔压住的时候，网孔也会变得不那么有效。