[单选] Wide Area Network (WAN) is a computer network that covers a broad areA. Which statement is correct for wide-area network (WAN)?（）

What are the characteristics of the process of documenting the layers of an existing network? （） begins with gathering organizational input that may be inaccurate。 begins with gathering organizational input that does not need to be supplemented by a network audit。 requires a network audit to support some upgrade decisions。 requires a network audit to support any network restructuring。 provides reliable input for verifying network consistency。 does not provide reliable input for designing change。 以下不属于植筋技术特点的是（）。 对以原桥梁梁体作为固定的基材不产生膨胀力。 适宜边距、间距大的部位。 施工快捷简便，容易掌握，硬化时间短，可以缩短施工工期。 承载力（剪力、拉力）高。 How do Cisco Unified Communications IP phones receive firmware upgrades?（） user request using the keypad of the phone and HTTP download。 IT department scheduled upgrade using HTTP download。 TFTP download based on version control through Cisco Unified Communications Manager。 FTP download based on version control through Cisco Unified Communications Manager。 HTTP download based on version control through Cisco Unified Communications Manager。 On a cisco aironet 1130ag series standalone access point,the status led is dark blue and blinking. What does this indicate？（） the internal radio has failed.。 a firmware upgrade is in progress.。 an access point buffer overflow is occurring.。 the access point is booting.。 边坡破坏主要形式之一（）。 侧向位移。 岩爆。 崩塌。 Wide Area Network (WAN) is a computer network that covers a broad areA. Which statement is correct for wide-area network (WAN)?（）