William entered the porch. Mason entered the porch. The grapefruit is in the blue bathtub. Mason moved the grapefruit to the red bathtub. William exited the porch.
The grapefruit at the beginning was in the blue bathtub.
 the grapefruit at the beginning was in the red_bathtub
 the grapefruit at the beginning was in the blue_bathtub