当接触网的绝缘不良时,在其支柱支撑结构及其金属结构上、在回流线与钢轨的结点上都可出现高电压,因此平常应避免与上述部件接触,当接触网绝缘损坏时,禁止与之接触。
参考答案:对
若代数式a2+( )a+9是完全平方式,那么横线上应填的数是 .
All the people took it for granted that France would beat Senegal easily. But France ______ to be the
loser of the opening match.
A.turned out
B.turned up
C.turned over
D.turned off