To allow a regular user account to mount and unmount a filesystem （for instance， a cdrom or floppy）， which option need to be added to the corresponding line in /etc/fstab？（）

多项选择题WhatdoestheFilesystemHierarchyStandardenable？（）

A. software to predict the location of installed files and directories
B. software to predict the ownership and access rights to files and directories
C. users to predict the location of installed files and directories
D. users to predict how the filesystem should be formatted according to need

单项选择题Youarelookingforanexecutablefilefoo.Selectthecommandthatwouldsearchforfoowithindirectoriessetintheshellvariable，PATH.（）

A. locate
B. which
C. find
D. query
E. whereis

单项选择题Whichofthesecommandsallowsyoutousesharedlibrariesthatarein usr local lib？（）

A. export LD_PRELOAD=/usr/local/lib
B. export LD_LIBRARY_PATH=/usr/local/lib
C. Idconfig /usr/local/lib
D. Idd/usr/local/lib

单项选择题Usingvi，youwanttosavechangestothefilemyfilewith：w!，butvicomplainsitcannotwritetothefile.Therefore，youwanttocheckthewritepermissionsonthefile.Todothiswithoutleavingvi，youtype：（）

A. ：!ls-I myfile
B. ：\ls-l myfile
C. esc ：Is -I myfile
D. ：？ls-l myfile

单项选择题YouwishtokillaprocesswithaPIDof123.Selectthecommandwhichexiting.（）

A. kill-1 123
B. kill-9 123
C. kill-15 123
D. kill-17 123