Children are canoeing on a beautiful lake.
The kids are climbing a mountain.
One activity, canoeing on a lake, requires water and a canoe while the other, climbing a mountain requires climbing equipment and a mountain (land).
exists e1 s1 x1 x2.(on(e1,x2) & n_lake(x2) & a_beautiful(s1) & Theme(s1,x2) & Actor(e1,x1) & v_canoe(e1) & n_child(x1))
exists e1 x1 x2.(n_kid(x1) & Theme(e1,x2) & Actor(e1,x1) & v_climb(e1) & n_mountain(x2))