Which of the following types of galaxies are most spherical in shape?
A) spirals
B) ellipticals
C) lenticulars
D) irregulars
Question 2
Galactic disks appear blue because
A) they contain no G, K, or M dwarfs.
B) they contain only blue reflection nebulae.
C) dust obscures the longer, red, wavelengths.
D) O and B blue giants are much brighter than G, K, or M dwarfs.
E) dark matter gravitationally shifts all wavelengths towards the blue.