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.
　　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。

　　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.
　　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。

　　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.
　　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。

　　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 requires only half the fuel energy that the internal-combustion powered car does to go the same distance.
　　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。