______ represent significant barriers to the flow of surface ocean currents, which normally flow in the direction of prevailing winds.

The four major depth zones are:

_________ is the proportion of a material that is made up of spaces.

Most near earth objects burn up in the ____________.

__________ is the temperature air must reach in order to become saturated.

The subscapularis muscle performs which of the following actions?

Lightning forms when:

Why does precipitation form when air moves up a mountain?

What are the three compositional layers in the Earth’s interior?

Which clouds are associated with rain?