Answer:
298.9 million years ago - 251.902 million years ago
Explanation:
It might be in the 2011 Earth Science Review Packet so maybe go check that out
And I don't exactly get what you are trying to ask hit me back up though
Answer:
Random samples
Explanation:
It needs to be random so that there isn't bias that would skew the consistency
Answer:
Well they help us understand the properties of matter of course!
