What is one negative effect of human influence on cycles of matter?

Using complete sentences, explain the differences between a command economy and a market economy. what type of economic system is created when these two systems are combined? what are the benefits of combining these two systems?

The impact of a large asteroid comet with earth has been proposed to have caused the extinction of the dinosaurs. the impact site of this comet is in or near

Impressions of tropical swamp plants were observed on rocks in polar regions. the impressions were dark black imprints, which means the fossils are examples of ( 1 ) the fossils tell us that polar regions ( 2 ) ( 1 ) a. carbonization b. mineralization c. trace fossils ( 2 ) a. had tropical plants that can grow in ice b. might have had a diffierent climate in the past c. will have abundent vegitation