Sentence:Having been won over by the slick downiness of a paddling of ducklings nibbling bread crumbs on the central pond, I was irritated to see their place taken by a [e1]squabble[/e1] of [e2]seagulls[/e2].
 e1: squabble. 
 e2 : seagulls.
Answer: Member-Collection(e2,e1)