Answer the following question given this paragraph: 

A model serves a useful purpose – it gives us an idea of what the real thing is like. The model plane seen above has wings, a tail, and an engine just like the real thing. This model also has a propeller, as is the case with most small planes and some smaller passenger planes. However, the model is not the real thing. We certainly cannot fly people or cargo in the model (besides maybe a tiny mouse), but we can get some idea of what a real plane looks like and how it works.


Q: What are models good for?


A:
they give us an idea of what the real thing is like