1. What is Science? A. The goal of science is to investigate and understand the natural world, to explain events in the natural
world, and to use those explanations to make useful predictions.

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.

there is none because earth is stationary and flat.