Recovery; difference between 恢复 and 康复
恢复 usually means recovering from a state to the original state, almost always implies getting back to the normal and good state. It can be used abstract as well, such as people's mood or a certain feeling. Thus it is not necessary for describing physical things or conditions.

康复 is much more specific. It's always related to health since 康 can mean health in Chinese, meaning completely recovering from an illness. And it can be used to animals, but not plants(but if you are a writer and you're using personification, that's fine to use the word). Keep in mind that people don't really say 康复 from just a flu or a tooth pain which is not severe. People tend to use it more often on serious conditions like a surgery, especially that last long and require you to rest in bed. Although it makes perfect sense to say this word, it is pretty much in formal conversations or letters that I would be more likely to use it. When in a casual context that people know you're talking about the sickness, just say '好了' to mean 'recovered' and '好了吗？' to ask about if someone is recovered.