A group of children are walking in the sand.
Some kids are walking at the beach.
The phrase a group of children itself shows that they are kids and walking in the sand indicates that they are at
exists e1 x1 x2 x3.(n_sand(x3) & in(e1,x3) & Actor(e1,x1) & v_walk(e1) & of(x1,x2) & n_child(x2) & n_group(x1))
exists e1 x1 x2.(n_beach(x2) & at(e1,x2) & Actor(e1,x1) & v_walk(e1) & n_kid(x1))