What could happen in planetary systems where the nebular gas is quickly disbursed?
A) No terrestrial planets would form.
B) The only planets would be more massive than Jupiter.
C) Many planets would be destroyed by migration onto the central star.
D) Large ice-rich planetesimals would not be able to gather hydrogen and helium and become gas giants.
Question 2
Why does the burning of fossil fuels increase the greenhouse effect on Earth?
A) Burning depletes the amount of ozone, thereby warming the planet.
B) Burning fuel warms the planet.
C) Burning produces infrared light, which is then trapped by existing greenhouse gases.
D) Burning releases carbon dioxide into the atmosphere.
E) All of the above are true.