Alpha and delta waves. Delta waves are common during deep sleep in which dreams and R.E.M. Occurs.
The Doppler radar used in weather forecasting measures the direction and speed, or velocity, of objects such as drops of precipitation. This is called the Doppler Effect and is used to determine whether movement in the atmosphere is horizontally toward or away from the radar, which aides in weather forecasting.
The answer is B: moist and hot with low density