The orbits of most comets
A) have perihelions within the orbits of Mercury.
B) are like the planets, fairly circular and in the ecliptic plane.
C) lie almost entirely beyond the orbit of Neptune.
D) go no farther out than Pluto, then return to the sun again.
E) are shorter than the 76-year period for Comet Halley.
Question 2
As their name implies, all planetary nebulae feature spherical shells and look like the disks of Uranus or Neptune.
Indicate whether the statement is true or false