You need a hypothesis a control a non control and experimental class you will have 3 sections and over the days u will record the changes
Answer:
prevents secretion of upper air passage
Explanation:
to prevent foods and drinks from falling down the airway which is called aspiration and may lead to pneumonia
Answer:
Human activities have a tremendous impact on the carbon cycle. Burning fossil fuels, changing land use, and using limestone to make concrete all transfer significant quantities of carbon into the atmosphere