How do living things recycle oxygen in earth's atmosphere?

Which statements describe resources? one of the factors people use when deciding where they will live is the availability of resources. renewable resources have little value for people. resources are unevenly distributed throughout the world. energy is the world resource which has the highest use. the use of nonrenewable resources has decreased in recent history. the use of resources is evenly distributed throughout the world. the world's oil supply will last for the next forty years if its use continues as expected.

Lactic acid and energy are produced in muscle cells during choose 1 aerobic respiration cellular respiration anaerobic respiration cellular division

What are some natural processes that represent physical and chemical changes?