contoh dialog cause and effect

A: Do you know why flying balloon can fly?
B: No. I don't know, tell me why.
A: Flying balloon can fly because the balloon is filled in with gas that is lighter        than the air. When the total weight of the balloon and the gas inside the              balloon is lighter than the air around it (for the same volume), then the balloon will fly.
A: Almost the same thing happen with the flying balloon that can carried people.  The air under the balloon is heated so that it is hot. When the air is hot it becomes lighter than the air around it that is not heated, as a result the balloon will fly.