单项选择题 WhichdaemonconvertsRemoteProcedureCall（RPC）programnumbersintoInternetportnumbers？（）

单项选择题 Whichcommandmustberunafteranadministratorhasmadechangesto/etc/servicestoactivatethechanges？（）

单项选择题 Multiple users are trying to telnet to the AIX server. They are able to ping the server successfully， but are getting the following error message：  telnet： connect： A remote host refused an attempted connect operation   Which of the following could be the cause of this problem？（）