题目

When Mary saw me, she didn't say Hello to me but went in the opposite _____________. A . request B . direction C . pattern D . situation 答案：B远距离输电中，发电厂输送的电功率相同，如果分别采用输电电压为U1＝110 kV输电和输电电压为U2＝330 kV输电．则两种情况中，输电线上通过的电流之比I1∶I2等于A.1∶1B.3∶1C.1∶3D.9∶1