The speaker points out the three disadvantages asserted by the reading passage attributed to the widely use of ethanol as a fuel is unconvincing.
As for the environment, the professor do argree that using ethanol as a resource can produce carbon dioxide, but he also points out that plants have the ability to remove the carbon dioxide. The ethanol is produced from the corn, and the corn can inhale as its nutrition . As a result the incresed use of ethanol will not increase the green house gas , and the temperature will stay stable
What is more, the speaker states that producing significant amout of ethanol will not reduce the food for animal. He says there is a specific plant which animal seldomly eat can be used to produce ethanol.
Finally, the professor also refute with the statement made in the passage, he insists that the price of enthanol would not increse, but it might decrese. The increasing using of ethanol will encourage people to produce more ethanol. The more the ethanol produce, the cheaper the prize will be.
From the resons the speaking material stated, we can simply make the conclusion that the incresing using of ethanol will not cause environment problem, lacking of food for animals and the high price of ethanol.