Choose the best answer.

1		The stars in space are _________________.
			A)	uniformly spread out.
			B)	distributed completely at random
			C)	chiefly in the Milky Way
			D)	mostly contained within widely separated galaxies
2		The Milky Way is ________________.
			A)	a gas cloud in the solar system
			B)	a gas cloud in the galaxy of which the sun is a member
			C)	the galaxy of which the sun is a member
			D)	a nearby galaxy
3		Relative to the center of our galaxy, _________________.
			A)	its starts are stationary
			B)	its stars move entirely at random
			C)	its stars revolve
			D)	Population I starts are stationary and Population II star revolve
4		Evidence of various kinds suggests that at the center of our galaxy is a ________________.
			A)	quasar
			B)	pulsar
			C)	neutron star
			D)	black hole
5		A radio telescope is basically a (an) _________________.
			A)	device for magnifying radio waves
			B)	telescope remotely controlled by radio
			C)	directional antenna connected to a sensitive radio receiver
			D)	optical telescope that uses electronic techniques to produce an image
6		Primary cosmic rays are composed largely of very fast ________________.
			A)	protons
			B)	neutrons
			C)	electrons
			D)	gamma rays
7		Cosmic rays _________________.
			A)	circulate freely through space
			B)	are trapped in our galaxy by electric fields
			C)	are trapped in our galaxy by magnetic fields
			D)	are trapped in our galaxy by gravitational fields
8		The red shift in the spectral lines of light reaching us from other galaxies implies that these galaxies _________________.
			A)	are moving closer to one another
			B)	are moving father apart from one another
			C)	are in rapid rotation
			D)	consist predominantly of red giant stars
9		According to Einstein's general theory of relativity, the universe _________________.
			A)	must be expanding
			B)	must be contracting
			C)	must be either expanding or contracting
			D)	may be neither expanding nor contracting
10		Supernova explosions have no connection with ____________________.
			A)	the formation of heavy elements
			B)	cosmic rays
			C)	pulsars
			D)	quasars
11		Current ideas suggest that what is responsible for the observed properties of a quasar is a massive __________________.
			A)	neutron star
			B)	black hole
			C)	spiral galaxy
			D)	star cluster
12		The age of the universe is probably in the neighborhood of ___________________.
			A)	15 million years
			B)	4 ½ billion years
			C)	15 billion years
			D)	30 billion years
13		The term big bang refers to _______________.
			A)	the origin of the universe
			B)	the ultimate fate of the universe
			C)	a supernova explosion
			D)	the formation of a quasar
14		The elements heavier than hydrogen and helium of which the planets are composed probably came from the ___________________.
			A)	sun
			B)	debris of supernova explosions that occurred before the solar system came into being
			C)	big bang
			D)	big crunch
15		Today the universe apparently contains ________________.
			A)	only matter
			B)	only antimatter
			C)	equal amounts of matter and antimatter
			D)	slightly more matter than antimatter
16		Radiation from the early history of the universe was doppler-shifted by the expansion of the universe until today it is in the form of _________________.
			A)	x-rays
			B)	ultraviolet waves
			C)	infrared waves
			D)	radio waves
17		Present evidence suggests that most of the mass of the universe is in the form of ________________.
			A)	dark matter
			B)	luminous matter
			C)	cosmic rays
			D)	black holes
18		It is likely that the planets, satellites, and other members of the solar system were formed _________________.
			A)	together with the sun
			B)	later than the sun from material it ejected
			C)	later than the sun from material it captured from space
			D)	elsewhere and were captured by the sun
19		Planets are always small compared with stars because otherwise ________________.
			A)	the rotation of the planets would cause them to disintegrate
			B)	the great mass of the planets would cause them to be pulled into their parent star
			C)	the great mass of the planets would prevent them from being held in orbit and they would escape
			D)	the planets would be stars themselves
20		The least likely reason why planetary systems have not been directly observed around stars other than the sun is that ___________________.
			A)	planets are small
			B)	planets shine by reflected light
			C)	planetary systems are rare
			D)	other stars are far away