It means don't be expecting much. When people hold their breath, they are waiting for something to happen. WHen people give the advice of dont hold your breath, they are saying taht there isn't anything going to happen
Explanation:
Jordan Baker hates Tom Buchanan but works tirelessly to really get Daisy separated from him, at least for a short time, by facilitating Daisy's relationship with Gatsby. Tom, while ignorant that Jordan is operating toward him across his back, doesn't really like Jordan but feels he could use herself.
Achilles enters the battle to avenge the Patroclus;s death. I am pretty sure this is right, because this is what I am studying right now too! :)
A, bias because it is their opinion, and not based on facts