The Howling of Wind on a Blustery Night Is Believed

Multiple Choice

The howling of wind on a blustery night is believed to be caused by

A) variations in air temperature.
B) winds blowing around a frozen surface.
C) ​snowflakes striking one another but not sticking together.
D) ​air flowing past obstructions.
E) ​wind lifting,then lowering small objects at the surface.