For the four-sentence (S1 to S4) paragraph below, sentences S1 and S4 are given.
From the options P, Q, R and S select the appropriate sentences for S2 and S3, respectively.

(S1) The men and women took their places after the initial mingling, and immediately a surge of conversation filled the room.
(S2)
(S3)
(S4) One or two of the women were actually bouncing up and down on the sofa cushions.

(P) So, the two parties had to lean forward, their elbows on their knees.
(Q) At the beginning they mingled awkwardly, clutching their drinks, and walking here and there.
(R) Several people made a last-minute dash to the bathroom before the conversation could start.
(S) The men’s chairs were far enough away from the women’s couches.