Mr.Obama smiled and joked throughout the forum,and earlier, as he toured the community college's wind turbine lab.
VOA: standard.2010.01.22
(SAYING) Here at the GM battery lab, the Volt's 16 kilowatt lithium ion batteries are run through the rigors of extreme driving,weather fluctuations and abrupt movements.
VOA: standard.2010.07.30
应用推荐