Oil, natural gas, and coal are considered to be nonrenewable resources. why are these fuels considered to be nonrenewable?

Which of the following is a difference between a food chain and a food web? selected: a. food webs contain both plants and animals. food chains only contain animals.this answer is incorrect. b. food webs show energy transfer. food chains show which animal eats which animal. c. food webs separate organisms by tropic level. food chains do not. d. food webs are a complex patterns of energy flow. food chains only show one line of energy flow.

Which kind of worm has a closed circulatory system? a planarian b fluke c pinworm d an earthworm

1. -define adaptation2 explain darwin's theories of descent with modification and natural selection in detail3. -explain how each of these provides evidence for evolution: a. -fossil record, including superposition and transitional fossilsb-anatomy, including homologous structuresc-biological molecules, including dna and proteins4. -explain the difference between convergent and divergent evolution.5. -define and give three examples of artificial selection6. -define and give one example of coevolution.7. -explain biodiversity and how it benefits humans.8. -explain a type of population lest affected by environmental change.