The correct answers are:
B. Warmer air promotes more evaporation.
D. Humidity refers to the amount of water vapor in the air.
E. Areas with a lot of surface water have higher humidity than drier areas.
The humidity can simply be described as the amount of water vapor in the air. The humidity can vary, and it can be very high in certain place for the whole year, very low at other places for the whole year, or to be changing seasonally.
The areas that have a lot of surface water (the Amazon River Basin) tend to have higher humidity than the places that lack surface water (Sahara Desert). Also, the humidity depends a lot on the temperature of the air. The warmer the air is, the higher the humidity, and vice versa, the colder the air is, the lower the humidity.