Creatures that are very sensitive to the changes in the air before a storm can “predict” a change in the weather. (2) birds, for example, sense the pressure change and fly lower. (3) low-flying birds, then, indicate that rain is coming. (4) similarly, houseflies detect this change and move indoors to avoid the downpour. (5) and cats are known to groom themselves just before a storm. (6) in doing so, they are reacting to the static electricity that enters the air before a thunderstorm. (7) the electricity separates their fur and makes them feel dirty, so they lick themselves to make the fur smooth and “clean” again. the sentence that expresses the main idea is: (choose the number of the sentence.)