Answer:
She predicts that Mr. Birkway helped hide Mr. Cadaver's body under the rhododendron
Step-by-step explanation:
Phoebe is paranoid and is convinced that Cadaver is a murderer and in his backyard there re many bodies buried there. However Sal enjoys thinking about the evils of Cadaver because he hated the fact that her father spend more time with women.
A surprise happens when Birkway pulls Cadavers driveway, who was their English teacher. While Birkway is helping Cadaver in digging rhododendron bush. Phoebe and Sal are at their mission of spying on them. Sal suggest they put up a grocery, but Phoebe tell her that is the work that her mother enjoy doing.