多项选择题
A. enhanced multilayer software image
B. connectivity to multiple types of WAN connections
C. Cisco Unified Communications Manager
D. QoS for converged networks
E. modular， customizable components
单项选择题 Given the HttpServlet code： getServletContext（）.setAttribute（“foo”， “value”）； What is the result？（）
问答题 恢复当前目录中所有已经删除的文件，提示确认信息。
单项选择题 A router that performs Network Address Translation （NAT） is installed between your computer and the Internet. The router fails. You connect the computer directly to the Internet. You need to ensure that the computer is connected to the Internet in the most secure manner possible. What should you do？（）