True or false. a good critic can manage to not be affected by her own bias and experience

True, if a critic allowed bias and past experiences to affect his/her review of a work, then that critic would be no different than an average person giving an opinion. 

The mode of persuasion "ethos" appeals to beliefs or ideals of a community and also an authority figure's character or credibility to influence individuals through morals.

In the famous play "Julius Caesar", Mark Anthony changed the opinion of the Romans by making them hate Brutus and the conspirators using "ethos" to put their credibility on the spot with irony and sarcasm when he repeatedly calls them "Honorable Men"; on the other hand he praise Caesar's loyalty to him when he calls him "His faithful friend", making people empathize with his character.