A__________is an otherwise normal spiral galaxy with an unusually bright, small core that fluctuates in brightness.
A) pulsar
B) blazar
C) Seyfert galaxy
D) Markarian galaxy
Question 2
Of all the galaxies, _____ are easiest to notice.
A) elliptical galaxies
B) spiral galaxies
C) lenticular galaxies
D) dwarf spheroidal galaxies