The cell membrane functions most like!e a (n)

A barrier keeping unwanted substances out

Explanation: Hope this helps<3

a security guard

Explanation:

The cell membrane is like a security guard because it controls what goes in and out of the cell.

allowed for the prediction of the properties of missing elements.

the main thing i would use is bricks because if there is a hurricane, there is a great possibility for the house to still stand. and i would also use plexiglass windows instead of regular windows because plexiglass isn't prone to breaking.