The cell membrane controls what comes in and out of cells.
the cell membrane
If you mean the cell membrane, it keeps lets things in and out of the cell.
What is the word thatWhen a membrane allows some things in but keeps others out
A common misconception about the cell wall is that it lets things in and out of the cell. It does not. It simply keeps the cell firm and together.
How about a fence around a yard? It does the same thing as a plasma membrane, it keeps the things that are supposed to stay in the yard, in the yard. And, it keeps the things that are outside the yard from getting into the yard. Every once in a while it lets a few select things either go in or out.
gravity keeps things in orbit
For one thing, it's spelled PLASTIC WRAP and two. Aluminum foil keeps things cool, or cooler by how good it is as a insulator. It lets the temperature sort of flow through where it needs to go. And you can kind of control this by rolling the foil thicker or thinner.
Cotton keeps most things warm.yarn keeps things warm to
The male keeps it safe and when there ready he lets them go.
so you bagge keeps things in and storaged, what keeps things out and available?
It keeps the eyes moist which keeps them healthy which lets us see properly which can help us survive.
This is an observation