Answer:
Doze<em>n's</em> of people have volunteered to help out at the marathon tomorrow.
<em><u>Dozens of people</u></em> have volunteered to help out at the marathon tomorrow.
The voluntee<em>r's</em> jobs include giving directions and distributing water and food.
The <u><em>volunteers' jobs</em></u> include giving instructions and distributing food and water.
The function of that sentence is to provoke further thought and potentially action. I hope this helps.
Explanation:
"there" is the correct homophone its the only one that makes sense.
A really dumb one!!