Why aren't there many samples of Earths original
crust anymore?

c

explanation:

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:

during the early years of world war i, the germans used "the submarine" to a great advantage