什么是眩光？眩光有什么危害？
Which of these is the best definition of the Cisco Lifecycle Services approach？ Select exactly 1 answer（s） from the following：（）。 ["It defines the minimum set of services required to successfully deploy and operate a set of Cisco technologies","It determines how best to price Cisco products","It provides partners with a useful way to leverage Cisco resources","It consists of these phases： plan， deploy， support， and troubleshoot"]
脱索保护是用来能护什么？支架上脱索保护开关的连接方式？
当二氧化碳浓度超过一定限量时，往往会不知不觉地使人、畜及其它动物缺氧，甚至窒息致死。其窒息原因是（）。 ["具有毒性使人肌体、器官失去功能","和人体的蛋白质结合","和人体的血红蛋白结合","具有刺激和麻醉作"]
非晶
电站（所）的设备评级应（）一次，每季（）一次。
