For many of their illnesses scientist and doctors haven't treated them before so they don't know how to treat them or exactly if the animal can handle the treatment
These fuels are nonrenewable because they are limited substances which cannot be produced at the same rate at which it is used. Also, they cannot be REused, hence the wording non-REnewable. Hope this answers your question.
Answer: Excretory
Explanation: My grandpa went through this recently and I had to learn all about it. :(
