if you press combinations of keys and then press other keys, the system may be rebooted or the desired character may not be written
https://photos.app.goo.gl/LjD86iD1TuJGPumW7
and this works not only in open OS but also in other systems, for example Mine OS:
https://photos.google.com/search/_tra_/photo/AF1QipN7bO5ws7CCPzoYUKFE-kUkijeGI3gfdZYXGQJ1
and the system crashed when i pressed ctrl or alt

what you are seeing is the effect of ^d (ctrl+d)
it is the same as the exit command

That's not what I meant! after I press CTRL+D (or something else) then almost every button becomes work as CTRL+D