Al-ma'mun founded the house of wisdom in order to

answer: the 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:

ww1 weapons: tank. tanks were used for the first time in the first world war at the battle of the somme. they were developed to cope with the conditions on the western front. the first tank was called 'little willie' and needed a crew of 3.