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

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

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

A. tr ’\r\n’ " < userlist.txt > newlist.txt
B. tr -c ’\n\r’ " < newlist.txt > userlist.txt
C. tr -d \r¯ < userlist.txt > newlist.txt
D. tr \r¯\n¯ userlist.txt newlist.txt
E. tr -s ®^M’¡®^J’ userlist.txt newlist.tx

A. foo and bar would both be removed.
B. foo would be removed while bar would remain accessible.
C. foo would be removed， bar would still exist but would be unusable.
D. Both foo and bar would remain accessible.
E. You would be asked whether bar should be removed.

A. -remove removes the program， -purge also removes the config files
B. -remove only removes the program， -purge only removes the config files
C. -remove removes a package， -purge also removes all packages dependent on it
D. -remove removes only the package file itself， -purge removes all files related to the package

A. the process id of last background command
B. the exit status of the last command
C. the exit status of the last background command
D. the process id of the current shell
E. the name of the command being executed