Is “Dentists all over the world are telling their patients the same things. You must floss regularly” an example of Ethos and why

No. It isn't an example of ethos.

Explanation:

Ethos refers to an argument that's based on the credibility of the person that's making the argument.

Ethos simply means establishing the authority to speak on a particular object subject. It's the persuasion and the argument whereby the knowledge, good moral character and the credibility of the speaker is shown.

In this case, the example given isn't an example of ethos because dentists in this case is a broad term and therefore does not give credibility from a particular dentist or probably a dental research.

one context clue that me find the meaning of luxuriance was that the base word of luxuriance is luxury, so i think that luxuriance means something that is luxury, or something luxurious.

why? ? and you will probably get ban

explanation:

yes a mod can probably ban you, and will if you continue to spam. i don't know why you would want to be ban.