Spectators about to watch a woman use a drill.
A teacher is instructing her class how to use a drill.
The spectators in sentence 1 are not described as being taught by a teacher. The teacher is only mentioned in regards to her class in the second sentence.
exists p1 s1 x1 x2.(a_topic(x1) & Topic(s1,p1) & Actor(s1,x2) & a_about(s1) & all x3.(n_drill(x3) -> exists e1 x4 x5.(Theme(e1,x4) & Actor(e1,x2) & v_watch(e1) & for(x4,x3) & n_use(x4) & of(x4,x5) & n_woman(x5))) & (x1 = x2) & n_spectator(x1))
exists e1 p1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_instruct(e1) & Topic(x2,p1) & exists e2 x3.(Theme(e2,x3) & Actor(e2,x2) & v_use(e2) & n_drill(x3)) & n_class(x2) & of(x2,x1) & n_female(x1) & n_teacher(x1))