A bearded man with a nose ring is brushing his teeth.
A guy is preventing cavities
brushing his teeth and preventing cavities are similar.
exists e1 s1 x1 x2 x3 x4.(Theme(e1,x4) & Actor(e1,x1) & v_brush(e1) & n_tooth(x4) & of(x4,x1) & n_male(x1) & with(x1,x2) & n_ring(x2) & of(x2,x3) & n_nose(x3) & n_man(x1) & a_bearded(s1) & Theme(s1,x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_prevent(e1) & n_cavity(x2) & n_guy(x1))