Concept:Desert temperatures change sharply between day and night because there are no clouds to trap heat.
Explanation:In deserts, the sky is usually clear and cloudless.
During the day, the ground absorbs strong sunlight and becomes very hot.
At night, without clouds to hold the heat near the ground, the warmth escapes quickly into the atmosphere.
As a result, nights become very cold while days remain very hot.
This creates a high daily range of temperature.
Answer:B. the sky is cloudless