What type of rock comprises most of the exposed surface of earth (75%)?

Seed plants that lived during the carboniferous impact life on earth today because a. they are the ancestors of all plant life on earth. b. their remains formed coal, which is an important resource. c. they produced fossils that are used to date many geologic events. d. their presence caused oxygen levels to drop, allowing animals to evolve.

The percentage of people in the united states engaged in agriculture in 2000 was approximately a. 56% b. 38% c. 21% d. 2%

Agriculture is a. slowly being replaced by mining as the primary industry in southern africa c. not possible in southern africa because of drought b. the primary industry in southern africa d. none of the above