The speaker thinks that ethanol is a good choice for fuel that can take place of gasoline, and offer three points rebut the passage.
Firstly, admitted that burning ethanol will not help reduce the emission of CO2, but in order to gain ethanol, people will grow more plants, which consume CO2 and hence remove green-house gas from air, thus contribute to the relief of global warming, which refute the first point of the reading passage.
Secondly, the production of ethanol will not cause decrease in food supply for eating and feeding animals as stated in passage, because ethanol can be made from the parts of plant that are not eaten.
这部分写的有些少,就一句话,because ethanol can be made from the parts of plant that are not eaten如果时间够用的话可以展开了写。It is true that we have to produce ethanol from plant, but only a specific part called cellulose, which is just from cell wall. Moreover, this specific part is not eaten by animals. So conclusion can be drawn that the number of animals' food will not be influenced by ethanol production.
Thirdly, the expenditure of ethanol will be competitive in the future compared with gasoline, not just resulted from subsidies as claimed in the passage. In the future, when more people use ethanol, the production will increase and it's price will fall. It's estimated that when the sales are three times bigger, the price of ethanol will drop 40%.
productivity triples, price will drop 40 percent,这个数据的例证加进去很不错。
总体评价应该算是 good了吧。😄