Hakeem is testing the effects of sunlight on samples of soil. which of these actions would introduce confounding variables into hakeem’s experiment?
he tests a theory that’s already been established.
he tests multiple hypotheses at a time.
he uses identical specimens when completing multiple trials.
he adjusts the independent variable and records the effects.
he uses different types of soil in each of his samples.

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.

Cells are adapted to preform specific functions. which of the following terms refers to this capability?

Archaebacteria use for movement. celia flagella pili cell walls