According to the theory of plate tectonics, what drives plate motion?

a) convention currents
b) magnetic reversals
c) volcanic eruptions
d) mid- ocean ridges

Which statement correctly describes a step-up transformer? a. it increases the amount of electric energy available. b. it increases the voltage of an electric current. c. it changes direct current into alternating current. d. it has more loops of wire in its primary coil.

The star betelgeuse is about 600 light-years away. if it explodes tonight, a. we'll know because debris from the explosion will rain down on us from space. b. we'll know it immediately because it will be brighter than the full moon in the sky. c. we won't know about it until 600 years from now. d. none of the above.

If the new moon happens on january 15th, what shape will it be on february 6th?