当网络出现连接故障时，一般应首先检查______。
A．系统病毒 B．路由配置 C．物理连通性 D．主机故障
参考答案：C
“What place is it？” “Haven’t you found out we _____ back where we ______？”
A．were, had been
B．have been, are
C．are, were
D．are, had been
腹泻超过多长时间为慢性腹泻
A．1周B．2周C．1个月D．2个月E．3个月
