During the hydrogen shell burning phase
A) the star grows more luminous.
B) the star becomes less luminous.
C) helium is burning in the core.
D) the core is expanding.
E) hydrogen is burning in the central core.
Question 2
How do human-built nuclear power plants on Earth generate energy?
A) chemical reactions
B) nuclear fusion
C) nuclear fission
D) converting kinetic energy into electricity
E) converting gravitational potential energy into electricity