<em><u>Semipermeable membrane is a type of biological or synthetic, polymeric membrane that will allow certain molecules or ions to pass through it by diffusion—or occasionally by more specialized processes of facilitated diffusion, passive transport or active transport.</u></em>
Explanation:
The real answer is It is a barrier with tiny openings that let some, but not all, materials pass through.
An observation is facts that you can conclude about an object using your senses. An inference is an educated guess based off some evidence and reasoning.