1, if it's glass, that's ok. But if it is a plastic cup, it is best not to, because the boiling water on the plastic will decompose toxins; As for canned food, it looks very unsanitary. So it's best not to be greedy and cheap.

2. The Coca-Cola cup of McDonald's can be served with boiled water, but the temperature can't be too high. I don't know how much longer I can hold on. I don't know how much longer I can hold on. You can also try to get a Coca-Cola cup at McDonald's to see if it can hold boiling water.