听力材料：

　　The reading is correct in pointing out the problems associated with oil-powered cars. Yes, oil is a finite resource, and yes, burning oil harms the environment. However, the reading is way too optimistic in its assessment of hydrogen-based fuel-cell engines. Hydrogen is not the solution to these problems.
　　阅读部分对于石油动力车的问题描述是站得住脚的。是的，石油是不可再生资源；是的，使用石油会造成环境污染。然而，阅读部分对于氢燃料电池内燃机的评论却过于乐观。氢燃料并不能解决这些问题。

　　First, hydrogen is not as easily available as the passage indicates. Although it’s present in common substances like water, it’s not directly useable in that form. For using a fuel-cell engine, hydrogen must first be obtained in a pure liquid state. This pure liquid hydrogen is a highly artificial substance. It’s technologically very difficult to produce and store liquid hydrogen. For example, it must be kept very very cold at minus 253 degrees Celsius. Imagine the elaborate cooling technology that’s required for that! So, hydrogen is not such a practical and easily available substance, is it?
　　首先，氢并不是像阅读部分说的那么容易得到。尽管氢就像水一样普遍存在，但是并不是以一种可以直接使用的形态存在的。如果想在燃料电池中使用氢，那么必须是液态纯氢。而这种液态纯氢是一种极难获取的物质。在技术上很难制造，同时很难储存。比如，液态纯氢必须保存在摄氏零下253度的超低温下。可以想象一下液态纯氢所要求的技术条件有多苛刻。由此可见，氢并不是一种很容易得到和使用的物质，是不是？

　　Second, using hydrogen would not solve the pollution problems associated with cars. Why? Producing pure hydrogen creates a lot of pollution. To get pure hydrogen from water or natural gas, you have to use a purification process that requires lots of energy that’s obtained by burning coal or oil. And burning coal and oil creates lots of pollution. So although the cars would not pollute, the factories that generated the hydrogen for the cars would pollute.
　　第二，使用氢燃料并不能解决汽车造成的环境污染。为什么？这是因为生产氢燃料的过程是会造成很多环境污染的。如果要从水或者天然气中获取纯氢，那么你就必须警醒能量消耗巨大的提纯。这种提纯过程所使用的能量则是来自于燃烧煤或者石油。众所周知，燃烧煤和石油是会造成很多污染的。所以，虽然汽车不会造成环境污染，但是那些为汽车生产氢燃料的工厂却会造成环境污染。

　　Third, there won’t necessarily be any cost savings when you consider how expensive it is to manufacture the fuel-cell engine. That’s because fuel-cell engines require components made of platinum, a very rare and expensive metal. Without the platinum components in the engine, the hydrogen doesn’t undergo the chemical reaction that produces the electricity to power the automobile. All the efforts to replace platinum with a cheaper material have so far been unsuccessful.
　　第三，当你知道制造燃料电池发动机有多贵的时候，你就不会认为使用它省钱了。价格昂贵是因为燃料电池发动机的原件是铂金的，而铂金是一种非常稀有而昂贵的金属。如果发动机不用铂金制造的话，氢就不能进行可以生产电能的化学反应，也就不能为汽车提供能量了。所有关于寻找成本低廉的铂金替代品的研究都还没有取得成功。

　　听力笔记内容：
　　Main point: not the solution.
　　Sub point one: not as easily available, pure liquid state, minus 253 degrees.
　　Sub point two: not solve, creates a lot of pollution, factories, hydrogen, pollute.
　　Sub point three: won’t, platinum, doesn’t undergo, unsuccessful.