In clear weather,the air next to the ground is usually ____ than the air above during the night and ____ than the air above during the day.
A) colder,warmer
B) colder,colder
C) warmer,colder
D) warmer,warmer

Question

Quizplus · Accepted Answer

During the night, the ground radiates heat to space, cooling the air in contact with it. This causes the air next to the ground to be colder than the air above it. During the day, the ground is heated by the sun, which warms up the air in contact with it, causing it to rise and be replaced by cooler air from higher altitudes. As a result, the air next to the ground is generally warmer than the air above during the day.

In Clear Weather,the Air Next to the Ground Is Usually