French 3.3.9 written assignment

Only answer if your sure / know what you're talking about! (do not guess)il vend des fruits de mer à é'm pretty sure it's not the first or the second, it's either "fish shop" or "butcher" no idea which.

Can somebody fully explain the “le passé composé régulier et irrégulier avec avoir” thing to me

French ! don't guess : ) what is the contraction for de + les? de les des