单项选择题
Your computer is unable to access external names or IP addresses. You need to connect to external Internet resources. What should you do first?（）
A.A B.B C.C D.D
You connect your computer to a wireless network. You di...
You connect your computer to a wireless network. You discover that this new connection fails to show in the Connect to a network window. You need to view this connection in the Connect to a network window. What should you do?（）
Your portable computer has a Virtual Private Network (V...
Your portable computer has a Virtual Private Network (VPN) connection configured. You need to connect to the VPN. What should you do?（）
You have a computer that runs Windows Vista. You need t...
You have a computer that runs Windows Vista. You need to prevent an application from connecting to the Internet. What should you do?（）
