anchor: well it's hard to say i mean while it's certainly the case that things like automobiles and factories uh pollute a lot um if you look at how much pollution is say kicked up by an active volcano uh it's certainly less than clear that anything man can do in this sort of scale of things has much effect at all what do you think
positive: Cars and factories cause a lot pollution.
negative: Factors and cars cause practically no pollution whatsoever.