SF6气体具有优良的灭弧性能和导电性能。
参考答案：错
With the change of red lights, there are long queues of vehicles that wait while a few people who walk across the zebra.
A．wait... walk
B．waiting... walking
C．waiting... walk
D．wait... walking
以下哪个不是事件营销特点（）
A.成本低
B.样式单一
C.效果明显
D.目的性强
