The Proterozoic division of the geological time scale is an era of the Phanerozoic eon. The Proterozoic division began 2.5 billion years ago and ended 542.0 million years ago.
Answer:
this pic is to blury sorry
Explanation:
420x6/7 = 360 starting amount
420-360 = 60 interest
60/360 = 16.67%
18.D
19.A
20.C
21.B
theses are going to be your answers
D - the earth is dynamic and constantly changing
