Children are learning about a firetruck.
The children are in a classroom.
Just because they are learning about a firetruck that doesn't imply that they are in a classroom doing it.
exists e1 x1 x2.(about(e1,x2) & n_firetruck(x2) & Actor(e1,x1) & v_learn(e1) & n_child(x1))
exists p1 x1.(n_child(x1) & exists x2.(in(x1,x2) & n_classroom(x2)))