A person is laughing on a roller coaster ride.
A person is riding on a roller coaster for the first time.
Sentence 1 is missing riding for the first time
exists e1 x1 x2 x3 x4.(on(e1,x2) & n_ride(x2) & of(x2,x4) & n_coaster(x4) & of(x2,x3) & n_roller(x3) & Actor(e1,x1) & v_laugh(e1) & n_person(x1))
exists e1 s1 x1 x2 x3 x4.(n_time(x4) & a_first(s1) & Theme(s1,x4) & for(e1,x4) & on(e1,x2) & n_coaster(x2) & of(x2,x3) & n_roller(x3) & Actor(e1,x1) & v_ride(e1) & n_person(x1))