单项选择题
A.DNS is not working properly
B.Ping is not working properly
C.The cables are disconnected
D.The device driver did not load properly
单项选择题 Ahostistobepartofaverysmallprivatenetwork，whichwillneverbeconnectedtoanyothernetworks.Whichofthefollowingnameresolutionschemeswouldbetheeasiesttoimplement？（）
单项选择题 Theinternetaddress198.102.27.120representswhichofthefollowingaddresses？（）
单项选择题 Whichofthefollowingadaptersshouldbeconnectedtocoaxialcablingwithouttheuseofmediaconverters？（）