A boy walks down the sidewalk with a trash bag while two other boys follow him.
A boy picks up litter while his classmates make fun of him.
A boy can carry a trash bag even if he is not picking up litter. Just because two boys are following a boy carrying a trash bag doesn't mean the boys are his classmates or that they are making fun of him.
exists e1 p1 s1 x1 x2 x3 x4.(n_male(x2) & n_sidewalk(x2) & exists e2 x5.(Theme(e2,x2) & Actor(e2,x5) & v_follow(e2) & -(x5 = x1) & n_boy(x5) & card_eq_2(x5)) & n_boy(x1) & n_boy(x1) & while(e1,p1) & a_down(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_walk(e1) & with(x2,x3) & n_bag(x3) & of(x3,x4) & n_trash(x4))
exists e1 p1 s1 x1 x2 x3.(exists e2 x1 x4.(of(e2,x1) & n_male(x1) & Theme(e2,x4) & Actor(e2,x3) & v_make(e2) & n_fun(x4)) & n_classmate(x3) & of(x3,x1) & n_male(x1) & while(e1,p1) & a_up(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_pick(e1) & n_litter(x2) & n_boy(x1))