How did westward expansion affect the population of the north

Sariah enters a room with several chirping crickets in it. upon first entering the room, sariah can hear the chirping; however, as she begins to talk to her friends, she is no longer aware of the chirping even though it is still there. the fact that sariah no longer perceives the chirping sound demonstrates sensory

Which statement about spreading knowledge of diseases and health around the world is correct?

Aconsumer is a buyer of services. true false