一般来说，盈亏平衡点越高，投资项目盈利机会就越多。
火灾探测原理，按照探测元件与探测对象的关系，可分为（） ["感光探测器","接触式与非接触式","感烟探测器","感温探测器"]
纯粹风险
教育观察的作用是什么？
Which two characteristics apply to Cisco Catalyst 6500 Series Switch supervisor redundancyusing NSF？（） ["independent of SSO","NSF combined with SSO enables supervisor engine load balancing","supported by RIPv2， OSPF， IS-IS， and EIGRP","supports IPv4 and IPv6 multicast","prevents route flapping","dependent on FIB table"]
旧事如新症
