化学反应器的空时就是反应物料在反应器内的停留时间，用来表明反应时间长短。
参考答案：错
I don’t know if I him this evening. If I him, I will give the novel to him.
A．will meet, will meet
B．will meet, meet
C．meet, will meet
D．meet, meet
如果用粗缆连接两台集线器，构建10BASE-T以太网，则两台机器的最远距离可达______。
A．500m
B．100m
C．700m
D．300m
