A) One reason why temperatures are cooler at higher altitude is that there is less atmospheric pressure and fewer air molecules to trap and retain heat.

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1. a) One reason why temperatures are cooler at higher altitude is that there is less atmospheric pressure and fewer air molecules to trap and retain heat. b) Another reason why temperatures are cooler at higher altitude is that higher altitudes are further from the Earth's surface, which absorbs solar radiation and radiates heat back into the atmosphere.

2. Two reasons why temperatures are cooler at higher altitude than at sea level are:

   • At higher altitudes, the air is less dense, meaning there are fewer air molecules to absorb and store heat from the sun.
   • The Earth's surface absorbs solar radiation and then re-radiates it as heat. Higher altitudes are further away from this primary heat source.

3. Altitude and temperature significantly influence where people live. Generally, people tend to live in areas with moderate temperatures and lower altitudes because these conditions are more favorable for agriculture, provide easier access to oxygen, and reduce exposure to extreme weather. High altitudes often have colder temperatures, lower oxygen levels, and harsher environments, making them less hospitable and leading to sparser populations.