How are 3-d printers useful in studying evolution ?

In what layer of the sun is energy transfers between atoms

Which of the following explains why a tree is often used as a model to represent the principle of common descent

Earths energy sources include both renewable and nonrenewable resources. name at least three sources of energy that could be used in your house. then describe the ideal energy source for generating most of your homes electricity, and explain why you chose that source. can someone give me some ideas, i’m kinda confused.