更多"When George W Bush delivered his St"的相关试题:
[单项选择] When George W Bush delivered his State of the Union Address this past January, three words appeared that had not previously been heard from the Oval Office: Switchgrass, stalks and woodchips.
Bush’’s signals on renewable energy have been decidedly mixed. Shortly before he visited the National Renewable Energy Laboratory (NREL) in Colorado last February, a $5 million funding shortfall forced the lab to lay off 32 workers. Bush blamed the layoffs, and NREL got its funding back.
Switchgrass is a fast-growing perennial plant native to the central and eastern U.S. and tolerant of many different soil types. To make cellulosic ethanol, switchgrass — or any cellulose-based plant — is broken down to make sugar, then fermented to make the fuel. Supporters say that when blended with petroleum products, ethanol from switchgrass results in a net energy gain of 334 percent, compared to just 21 percent for corn-based ethanol.
The cellulosic process has been invented and is being re
A. a biochemical product
B. a kind of animal
C. a kind of grass growing very fast
D. a kind of grass growing in a specific soil
