不幸的是，果实从树上落下后不能保存太长时间，3到4天后就开始发酵。

Unfortunately, the fruit does not keep long when off the tree and will start to ferment after about 3 or 4 days.

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如果希望某种技术在商业利用方面切实可行，首先在物料的预处理方面要求所得到的中间产品必须是容易发酵的糖份，产量高，浓度也较高，而且技术的实施成本还不能过高，还有生产过程中更不能使用有毒物质，不可以耗费太多能源，最后，所生产出来的草料油在价格方面必须能够与传统汽油一争高下。

They should not use toxic materials or require too much energy input to work. They must also be able to produce grassoline at a price that can compete with gasoline.

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啤酒和葡萄酒均在历史上只限于最高酒精含量约15 %，数量，超出酵母是不利的影响，不能发酵。

Beer and wine were historically limited to a maximum alcohol content of about 15% by volume, beyond which yeast is adversely affected and cannot ferment.

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