A. electromagnetic energy
B. electromagnetic energy travels through space
C. came from the sun
D. when a change in the nucleus of an atom takes place
E. when the sunrays are fierce
F. chemical energy is generated The energy stored in coal ______.

A．in
B．at
C．on
D．by

A．The same lessons.
B．Individual lessons according to their ability levels.
C．Individual lessons according to the teacher’s instruction.
D．Individual lessons according to their parents’ instruction.