At least: at least two can be more than two. For example, China has a population of at least 654.38+03 billion. Maximum: at most, two children can be 1, two children can be two, or even no children, but never more than two. For example, under normal circumstances, each couple can only raise 1 child at most, that is, they can only raise 1 child. If they don't do this, they will violate the law. Or: both, or one or more of them is enough. For example, I am a male teacher or a female teacher. If nothing else happens, I can be a male teacher. I don't have to be a female teacher, otherwise I don't want to be a man, hehe, joke. And: both, or both. For example, I'm a teacher and I'm from China, so if both are true, I can only be China and China. In addition, you can make an analogy. I'm a teacher and I'm from China. This shows that I can be a foreign teacher or not in China.