The sentences that contain an example of ethos are number 1, 3 and 5.
As a rhetorical device, ethos is grounded in the speaker's credibility, honesty or authority to involve the audience.
In sentence number 1, the fact that Gizmotry and Gadgetry has been active for 140 years implies that it has a good service and has been able to adapt and evolve with the market, so it can offer a better service.
In sentence number 3, all customer orders are right, or they're free the example of ethos is present in the display of confidence and authority and work ethic to the point that assure the customer that in the rare case that the order is not right, he or she will not have to pay for it.
In sentence number 5, the fact that the person prescribing the medication is wearing a stethoscope implies that he or she is a doctor with the knowledge and authority to prescribe Barco's medication.
I believe that the answer is “ they aren’t sufficiently brief” because the irony is that he’s expected to make brief summaries so since they aren’t brief then that’s irony.
Answer:
ease of access,
also if referring to present times... people would find it reassuring for the product to be clean
