List at least three functions of a cell membrane.

(1) they keep toxic substances out of the cell; (2) they contain receptors and channels that allow specific molecules, such as ions, nutrients, wastes, and metabolic products, that mediate cellular and extracellular activities to pass between organelles and between the cell and the outside environment; and (3) they separate vital but incompatible metabolic processes conducted within organelles.

-protects the cell -supports the cell -regulates materials entering and leaving cell

Bhope this : )

Humans can affect weathering and erosion in several ways.  humans cause  increases in acid rain and pollution, which increase the amount of  weathering  agents in the air and water, and then on land.for an easy answer: 1) acid rain2) pollution