Some energy experts and environmentalists have expressed skepticism about the benefits of biofuels, especially ethanol produced from corn.

VOA: standard.2009.09.02

The corn to ethanol conversion in the United States, and other things like that has really changed the world landscape in a lot of interesting ways.

在美国,很多类似于玉米制乙醇的技术,正以有趣的方式,改变着我们的世界

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

Some of that is being forced by the United States and the corn to ethanol conversion program that has pushed up the price of corn a great deal, pushed down the world supply of corn for eating, and pushed up world prices.

美国在一定程度上推动了这件事,玉米向乙醇转化项目,大大抬高了玉米价格,削减了可供食用玉米的供应量,世界玉米的价格就提高了

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

Corn-based ethanol produces only slightly more energy than it takes to produce it.

VOA: standard.2009.09.02

The bioreactors will grow algae that can produce ethanol fuel through a special process that involves using carbon dioxide from nearby coal-burning power plants to promote faster growth of the algae.

VOA: standard.2009.09.02