Answer:
A logical unit of a system.
Explanation:
i'm thinking your are talking about system layers such as the ISO? Layers help identify the order of how the whole system works.
It's neat organized and ready to find when needed
My opinion is the answers A and D. I would choose A if you can only choose one, though.
Answer:
You go to account settings, edit your profile and click preferences and then go to choose level and put which grade u are in the options r middle school, high school, and college
Explanation:
<span>Make eye contact look at everyone ur speaking to not just one person speak loud and clearly make sure your understandable</span>
