In order for a physical barrier to be effective in preventing infection, the barrier must . A. prevent the substance from entering the body, trap the substance when it first enters the body, or flush the substance out of the body B. destroy the substance before it enters the body, prevent the substance from reproducing, or flush the substance out of the body C. trap the substance in t

a

Explanation:

more words for this could be abiotic and biotic

abiotic: living organisms within an ecosystem

biotic: non-living organisms within an ecosystem

well first you need the sample of the temperature and gas level. i couldnt write a hypothesis unless i had some data. i think temperature changes will effect volumes of gas because gas changed into a solid or liquid at specific temperatures.