What is the first transition that signals the cause and effect pattern in this paragraph, please? (1) Why does lightning make such a loud sound? (2) The answer has to do with the electrical energy it gives off. (3) A single bolt may produce as much as 3,750 million kilowatts of electrical energy. (4) Most of this energy—75 percent—turns into heat, causing the temperature of the surrounding air to rise greatly. (5) Since heated air expands, the sudden increase in temperature leads to a rapid expansion of the air around the lightning. (6) And that air expansion causes sound waves—thunder—which can be heard up to eighteen miles away.