阅读材料：
Car manufacturers and governments have been eagerly seeking a replacement for the automobile’s main source of power, the internal-combustion engine. By far, the most promising alternative source of energy for cars is the hydrogen-based fuel-cell engine, which uses hydrogen to create electricity that, in turn, powers the car. Fuel-cell engines have several advantages over internal-combustion engines and will probably soon replace them.
One of the main problems with the internal-combustion engine is that it relies on petroleum, either in the form of gasoline or diesel fuel. Petroleum is a finite resource, someday; we will run out of oil. The hydrogen needed for fuel-cell engines cannot easily be depleted. Hydrogen can be derived from various plentiful sources, including natural gas and even water. The fact that fuel-cell engines utilize easily available, renewable resources makes them particularly attractive.
Second, hydrogen-based fuel cells are attractive because they will solve many of the world’s pollution problems. An unavoidable by-product of burning oil is carbon dioxide, and carbon dioxide harms the environment. On the other hand, the only byproduct of fuel-cell engines is water.
Third, fuel-cell engines will soon be economically competitive because people will spend less money to operate a fuel-cell engine than they will to operate an internal-combustion engine. This is true for one simple reason. A fuel-cell automobile is nearly twice as efficient in using its fuel as an automobile powered by an internal-combustion engine is. In other words, the fuel-cell powered car reqquires only half the fuel energy that the internal-combustion powered car does to go the same distance.
汽车制造商和政府都在积极地寻找内燃机的代替品，而目前内燃机是汽车主要的动力源。目前为止，氢燃料电池发动机是最有竞争力的汽车动力代替品。氢燃料电池发动机是用氢作燃料产生电能以充当汽车的动力。鉴于燃料电池发动机相对于内燃机发动机优点多多，因而可以很快替代内燃机。
内燃机发动机的问题之一就是对于石油的依赖，而石油具体的形式是汽油或者柴油。石油是不可再生资源，总有一天会用尽的。而燃料电池发动机所使用的氢则不是那么容易消耗完的。氢有多种来源，比如天然气和水。燃料电池发动机很容易得到，而这种能源的可再生性使其特别具有吸引力。
第二，氢燃料电池发动机还可以在全球范围内解决污染问题，这也是其具有吸引力的原因。使用石油不可避免的副产品就是二氧化碳，这是对环境有害的气体。而与此同时，燃料电池发动机唯一的副产品就是水。
第三，因为燃料电池发动机的使用费用比内燃机发动机低，燃料电池发动机很快就会在价格上很有竞争力了。这个道理是很简单的。燃料电池汽车的能量利用率几乎是使用内燃机发动机的汽车的两倍。换句话说，行驶相同的距离，使用燃料电池发动机汽车只需要消耗内燃机汽车的一半能量。
阅读部分需要提取的观点是：
- Main point: 氢燃料电池发动机将替代内燃机发动机
- Sub point 1:氢燃料来源丰富，不会用尽
- Sub point 2:氢燃料电池发动机不会污染环境
- Sub point 3:氢燃料电池发动机能量利用率高，更为经济
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.
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?
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.
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.
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。
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？
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。
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 |
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