A very substantial disappearance of organisms from the geologic fossil record provides evidence for which of the following events?
:
1) periods of mass extinction
2) a change in sea level
3) continental drift
4) a change in climate

Adeveloping nation's economy is based on a developed nation's economy is based on stay tuned- i may post some more questions from my study guide : )

Ms. ringer asked her class "what are the favorite colors of the students in our school" which student correctly deceives ms. ringer's question

Geologists know that potassium-40 decays to argon-40, with a half-life of 1.3 billion years. if an analysis of a feldspar crystal in a sample of granite shows that 75 percent of the potassium-40 atoms have decayed to form argon-40, what is the age of the granite