把一个底面直径和高都是62.8厘米的圆柱的侧面展开后一定是正方形。 [ ]
错误
读一读，把下列句子排成完整对话。
A. Jenny and Danny arrive today.
B. Good morning, Li Ming.
C. Sure. Let's take a bus.
D. Yes, I know.
E. Good morning, Mum.
F. May we go to the airport to meet them?
正确的顺序是: E ____________________________
试述工作接地的作用？
