I have a test in astronomy tomorrow, and I am trying to study right now for it
There are some things though that I can not figure out that I think are going to be on the test.

1) The comets of the Oort cloud are thought to have formed
where they are found currently.
in interstellar space far beyond the Sun's influence.
in the inner regions of the early Kuiper belt among the Gas Giant planets.

2)Titan has a thick atmosphere while Mercury doesn't can be attributed to more gas near Titan in the beginning.
Titan never suffering a catastrophic impact.
their respective locations in the solar system.

3)What is the primary difference between jovian and terrestrial planets?
color
luminosity
location within the solar system disk where they formed.

4)There is substantial difference between a high speed impact of either a comet (dirty snowball) or asteroid (rock and metal) with the Earth even if they have the same mass and speed.
true
false

5)The primary source for the Sun's energy production is
the Beryllium catalytic process.
perihelion pair production.
the Proton Proton cycle.

Thank you so much. I would greatly appreciate the help