敲开鸡蛋，看是否有异味。 将鸡蛋敲开并装在一个小盘子里，观察它的颜色。

I'm interested in that, but I only have a few mins. Can you give me at most the first 500 characters of a detailed explanation in English about that?
This is the best indicator of a bad egg. A bad egg will have a pungent, foul odor when you break it open. The sulfurous smell will be obvious as soon as the egg is cracked (and possibly before), and the egg should be thrown out. A bad egg will have this foul smell, regardless of whether it is raw or cooked. The color of the yolk will change based on the diet of the hen who laid it, so the shade of yellow or orange nothing to do with freshness. Instead, inspect the egg white, or albumen. If it is