If we don't do that ,there must be someone ______ do it for us.填一词

If we don't do that ,there must be someone ______ do it for us.填一词
If we don't do that ,there must be someone ______ do it for us.
填一词

If we don't do that ,there must be someone ______ do it for us.填一词
填else.其他
someone else 其他人