One of the Key Reasons That Professional Astronomers (As Opposed

Multiple Choice

One of the key reasons that professional astronomers (as opposed to the public) are interested in comets is that they

A) are beautiful to look at
B) are always omens of disaster
C) are icy pieces left over from the time that our solar system formed that can give us clues about that early time
D) are pieces splintered off one of the giant planets, so they can provide us with samples of their composition
E) are all visitors from other star systems, which can tell us about what conditions are like in distant reaches of the Milky Way Galaxy