Why can iridium sediment layer be used as evidence to support the main theory about the extinction of the dinosaurs

How was rockefeller able to build his monopoly across the oil industry? he found newer and cheaper ways to refine oil, increasing his profits. he confined his business to ohio so he could buy all the refineries there. he bought up oil refineries, cut costs, and reinvested his profits in other refineries. he began to sell kerosene as well as oil, expanding his market.

(easy 35 ) i am a confederate general during the civil war. who am i? 1. ulysses s. grant 2. robert e. lee 3. george mcclellan 4. winfield scott

Who was the founder of taoism whose name means "the old master"? a. laozi c. hanfeizi b. wu wang d. wu wudi