Select all that apply.

by world war i, five main power sources included:
water
steam
electricity
nuclear
coal
oil

he risk-return relationship. generally, the higher the potential return of an investment, the higher the risk. there is no guarantee that you will actually get a higher return by accepting more risk. diversification enables you to reduce the risk of your portfolio without sacrificing potential returns.

explanation:

this is a good question! i'll do some research and come back when i have the answer!