The plural form of the word radius is <em>radii</em>.
I know it sounds weird, but this is correct. Adding <em>-s </em> at the end of the radius would make the word grammatically incorrect. This is because the word radius itself is a Latin word.
- Marlon Nunez
Explanation:
a wide scattering of people who lived near rivers in temporary settlements of 1-3 households and practiced a mixture of hunting, gathering and crop growing
A. Because you will not be given a complete grade and teachers will consider it cheating and not allow your grade to be continued