以下为上下文.And here in the Midwest you have seen a boom in ethanol production and ethanol usage.And the reason why is,is that corn-based ethanol is leading an amazing change in the country.We consume about 5 billion gallons of ethanol right now in America.That's up nearly fivefold in a relatively quick period of time.The problem we face is that right now the most efficient way to make ethanol is through the use of corn

以下为上下文.
And here in the Midwest you have seen a boom in ethanol production and ethanol usage.And the reason why is,is that corn-based ethanol is leading an amazing change in the country.We consume about 5 billion gallons of ethanol right now in America.That's up nearly fivefold in a relatively quick period of time.The problem we face is that right now the most efficient way to make ethanol is through the use of corn