Air can be considered a mixture. which statement does not explain why?

Plants can have a positive and negative effect on the rate of weathering

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

Explain the value of statistics and other data to positive economics and to normative economics