There is less rainfall in the desert. Temperatures vary more in the desert. There is less water vapor in the desert air. There are fewer plants in the desert.
I gave my students this multiple choice question: Why does a town in the desert rarely experience early morning fog as compared to a town along the coast?

Only one answer is correct among these 4 choices:
- There is less rainfall in the desert.
- Temperatures vary more in the desert.
- There is less water vapor in the desert air.
- There are fewer plants in the desert.

Could you tell me which one is correct?

There is less water vapor in the desert air.