What word could be described as mesolithic era?

Perhaps Stone Age

Explanation:

Or just Stone, the Stone Age is what the Mesolithic Era is referred too because the majority of the buildings and tools that Humanity used were made out of Stone, so that's my best answer...

I hope this helps

his wha5

by using  production possibilities graph.  opportunity costs are key expenses in financial matters and are utilized as a part of registering money saving advantage investigation of a venture. such expenses, be that as it may, are not recorded in the record books but rather are perceived in basic leadership by processing the money costs and their subsequent benefit or misfortune.