电能单位的中文符号是（）
A.瓦[特]
B.度
C.焦[耳]
D.千瓦时
参考答案：D
The new-designed car is on show now. I wonder _____. [ ]
A. how much it cost
B. how much did it cost
C. how much it costs
D. how much does it cost
杜邦工艺停车降负荷操作时应保持各反应釜的液位。（）
