单项选择题 During system boot， the boot process hangs at LED 0551.  Which of the following is a likely cause（）

单项选择题 Whichcronentrywillrun/usr/local/bin/myscriptat0500everySaturday（）

单项选择题 A System p administrator wants to NFS mount a filesystem from server "alpha" to server "bravo".  Which of the following commands should be issued from "bravo" to determine which filesystems are being exported by server "alpha"（）