a circle fence sourrounding a small yard mesure 84 meters in length if you walk from one side from the other through the middle what is the distance across the small yard

Biomass can be used to generate electricity. biomass relies heavily on agricultural crops. plants release carbon dioxide and water in combustion. plants use photosynthesis to originally generate the energy that is needed. the chemical energy of these plants all started with what energy source?

Which of the following is not a type of epithelial cell

Which is an example of a vestigial structure? a: paw of a lionb: wing of a birdc: appendix of a humand: tail of a cat(i think it's a but i'm not sure)