1.Galaxies evolve by

1.Collisions between galaxies is thought to

1.The pregalactic blobs had masses similar to

1.A merger between two large galaxies of comparable size will most likely produce

1.Gravitational lensing of distant, faint irregular galaxies may be the key to

1.What is true of spiral galaxies?

1.Collisions between galaxies

1.What is the Great Wall?

Astronomers classify elliptical galaxies by

In this diagram, the galaxy at the left side is a(n) Galaxy Classification(1).png