托福听力练习：可替代能源

　　和谐英语网为同学们整理了托福听力练习集锦，供考生参考学习。

　　托福听力练习：可替代能源

　　Since we've been discussing alternative fuels lately, I wanted to pass on to you some information I read about a new fuel that's been in the news a lot lately.

　　It's called A-21.

　　It's composed of water and a chemical known as naphtha.

　　It seems to be a very promising fuel because it's much cleaner than the gasoline that we use today.

　　That's not to say that it doesn't pollute, but it is cleaner.

　　A-21 isn't like some other alternative fuels that require completely new types of engines.

　　A-21 still works in regular, everyday combustion engines like the ones in cars with only minor mechanical modifications.

　　So changing over wouldn't be a big deal.

　　You may doubt some of these claims as many researchers have.

　　Some people feared that because it contains about 45 percent water it would freeze in the winter.

　　But a small amount of antifreeze was added to it, and that seems to have solved the problem.

　　A-21 has recently undergone street tests in buses in Reno, Nevada.

　　So far it seems to work just fine.

　　This is a good thing, especially in Nevada, because the state government there has passed a law requiring that a large percentage of vehicles in Nevada run on alternative fuels.

　　A-21 should help.

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