Starting near the bottom, the float picks up heat from the warm surroundings, which causes the air to expand and the float to rise.
(the float; picks up; heat; from the warm surroundings) (the float; to rise; ) (the warm surroundings; causes; the air to expand) Context(the warm surroundings causes,List([55, 90))):(the air; to expand; )
the warm surroundings causes,List([55, 90))
the float the float the warm surroundings the air
picks up to rise causes to expand
heat from the warm surroundings
the air to expand