You already answered the question in the picture above
Human activities in the united states such as burning fossil fuels for electricity, heat, and certain transportation.
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Answer: When they were full of air, then the Pressure was the Highest 'cause of the larger force under the specified area as compared to when we released it. We decreased the area of our cheek, so pressure increased and air flows from the cheek (area of high pressure) to the atmosphere
Explanation:
