Answer:
it is called a mute
Explanation:
you dont put a trumpet into a trumpet to change the noise or a mop or a clarinet, so you would put a mute in, it kind of looks like a cup
Answer:
Be polite.
Explanation:
As the saying goes, kill them with kindness. If someone is being impolite, either 1, look at the situation i their shoes. Or 2, just simply keep on your professional face, don't lash out, don't act with hidden violence (Etc; slamming money on the counter for them to grab) Just simply apologize and continue working. You're only there for money, or to just have fun, or any reason at all. There's no need to have one person ruin you're mood.