Linux If the instruction is too long, how to enter the line, how to quickly delete the whole line of command, how to quickly move to the front of the command or the last

1. Example: How to use two lines to output if the instruction string is too long?
[Email protected] ~]$ cp/var/spool/mail/root/etc/crontab \
>/etc/fstab/root

"\enter" (\ Plus keyboard return) can be implemented

2.ctrl+u Ctrl+k, respectively, represents the cursor at the forward and the cursor at the next delete

3.ctrl+a Ctrl+e respectively represents the movement of the pipe to the front and last

Linux If the instruction is too long, how to enter the line, how to quickly delete the whole line of command, how to quickly move to the front of the command or the last