Two young girls drive an ATV.
The girls are driving.
The girls must be driving in order to drive an ATV.
exists e1 s1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_drive(e1) & ne_nam_atv(x2) & n_girl(x1) & a_young(s1) & Theme(s1,x1) & card_eq_2(x1))
exists e1 x1.(n_girl(x1) & Actor(e1,x1) & v_drive(e1))