Direct current is the flow of an electric charge

a. that regularly reverses direction

b. that regularly stops and starts again

c. that moves in only one direction

d. that stops at a specific point

Direct current =  that moves in only one direction

Explanation :

Electric current is defined as the electric charge per unit time. The electric current is of two types  

In direct current, the current flows one in one direction while in alternating current the current changes its direction periodically.  So, the correct statement that describes the direct current is " (C) that moves in only one direction ".          

explanation:

earth's surface is mainly heated by the absorption of infrared radiation from the sun.

evaporation occurs because molecules in liquid water are warmed ( usually by the sun) and vibrate quicker, becoming less dense and rise.

condensation occurs because molecules in water vapor are cooled and therefore vibrate more slowly thus becoming more dense and eventually fall to earth.

lines of equal barometric pressure on a weather map are called: isobars : lines of equal temp on a weather map are called: isotherms.​