How you would improve them modern day smart phones .

We could improve modern day smart phones by adding more storage, increasing it's speed, having more feature and changing the design of the phones to make them look more better.

Hope this helps!

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.