[问答题] 简述计算机病毒的危害。

关于钢筋混凝土梁受力特征的说法，错误的是（） ["梁的正截面可能出现的破坏形式有适筋、少筋和超筋破坏","梁的超筋破坏为脆性破坏","梁的正截面破坏形式与配筋率有关","梁的支座处易发生正截面破坏"] The following output was displayed on a switch.  Study the exhibit carefully. The administrator is verifying that a CEF FIB entry exists to destination network 192.168.150.0. Given the output generated by the "show ip cef" and "show adjacency detail" commands，  which three statements are true？ （） ["The "valid cached adjacency" entry indicates that CEF will put all packets going to such an adjacency to the next best switching mode.","The number 003071506800 is the MAC address of the source IP address.","There is a valid CEF entry for the destination network 192.168.150.0.","The number 003071506800 is the MAC address of the 192.168.199.3 next hop IP address.","The counters （0 packets， 0 bytes） indicate a problem with the 192.168.199.3 next hop IP address.","There is an adjacency for the 192.168.199.3 next hop IP address."] 衡量某一段时间内网站各网页被浏览的总次数的网站访问指标是什么。 如何备份与还原WINS数据库？ 皮带系统启动顺序与停止顺序（）。 ["一致","相反","无所谓"] 简述计算机病毒的危害。