Licensing usage for School Work

Hello:

Im a college student and Im using the “Design Ball” PowerPoint templates to do my presentations. I use the graphics for the nice professionalism and it really cuts down on my work.

Im not sure if I can use it for school purposes? If I can would I simply give credit to the authors at the end? Also, can I use it for multiple presentations and assignments since I bought the regular license?

Thank you so much for your time and help