缩短柴油机燃烧过程着火延迟期应选择()的燃料。
A.十六烷值高和蒸发性好
B.十六烷值低和蒸发性差
C.十六烷值低和蒸发性好
D.十六烷值高和蒸发性差
参考答案:A
高压输电过程中,输电电压为U,输电功率为P,输电导线上电阻为R,则下列说法中错误的是[ ]
A.损失功率为
B.损失功率为P2
C.电压损失为P
D.用户得到的功率为P-P2
______ she realized it was too late to go home.
A. No sooner it grew dark than B. Hardly did it grow dark thatC. Scarcely had it grown dark than D. It was not until dark that