Whether An Egg Is Fresh or Not?

An Fresh Egg

How do you know whether an egg is fresh or not?
When eating hot pot, some people would either put the evv directly into the pot or use it with Sha Cha as a sauce.
The important point is that if the egg is fresh, it will be delicious, if it's not fresh, you might end up going to the emergency room.
There are two ways of discerning whether an egg is fresh or not:
1. Observe whether the surface is bumpy and/or rough; the more the fresher.  On the contrary, the smoother it is the less fresh it would be.
2. When you soak the egg in cold water, if the egg is....
* .... laying flat, it is fresh.
* .... tilted in the water, the egg is 3-5 days old.
* .... floating on the water, the egg is spoiled.