Two specific reasons that the serial comma should be used in your writing.

A serial comma should be used for the two following reasons:

1. It should be used before a coordinating conjunction (before and or or ) with three or more items. For example:

I bought fruit, vegetables, and bread.

I went to the cinema, to the supermarket, to the post office, and to the bank.

2. In order to avoid ambiguity and confusion. For example:

I talked to my parents, Rebecca and Luis.

I talked to my parents, Rebecca, and Luis.

(In the first sentence, we assume that the writer's parents are Rebecca and Luis, while in the second one we assume that the speaker talked to four different people, to his/her two parents, to Rebecca and to Luis. So, the use of the serial comma is the only way to lead the reader to the correct conclusion.)

(Hope this helps) Sky

impartial means: treating all rivals or disputants equally; fair and just.

i would say that impartial is agreeing with something, because impartial means to treat your rivals, arguments, and reasoning equally and fair. so if you rival says something, agreeing on it means you did the impartial.