A man being bucked off a bronco at a rodeo.
The bronco is being treated humanely.
A bronco is a general statement while The bronco is allot more specific.
exists e1 x1 x2 x3 x4.(a_topic(x1) & off(e1,x3) & at(x3,x4) & n_rodeo(x4) & n_bronco(x3) & Theme(e1,x2) & v_buck(e1) & (x1 = x2) & n_man(x1))
exists e1 s1 x1.(n_bronco(x1) & a_humanely(s1) & Manner(e1,s1) & Theme(e1,x1) & v_treat(e1))