During the Carboniferous Period,
A) the carbon dioxide cycle started to operate for the first time
B) carbon-rich meteorites impacted the Earth
C) the first carbon-based life appeared
D) land was covered with dense forests with the appearance of the first insects and amphibians
Question 2
An alternative to the nebular theory for the formation of the solar system suggests that the planets formed from blobs of gas that had been gravitationally pulled out of the Sun during the near-collision with another star.
This idea is referred to as the A) fragmentation hypothesis
B) collision-ejection hypothesis
C) encounter hypothesis
D) tidal distortion hypothesis