A girl 's hands , another person 's feet , and a boy playing bongo drums sit on a picnic table .
It is probably the case that a boy playing bongos entertains his friends in the park .
It is probably the case that a boy playing bongos entertains his friends in the park .
We doubt that a boy playing bongos entertains his friends in the park .
A boy playing bongos entertains his friends in the park .