A、ash B、bash C、ksh D、csh E、zch
A、echo The current working path is $PWD. B、echo 'The current working path is $PWD.' C、echo "The current working path is $PWD." D、echo "The current working path is `pwd`."
A、alias copy="cp" B、alias copy='cp' C、alias copy=`cp` D、alias copy=cp