Which unit of geologic time is gthe shortest and most recent?
- cenozoic era
-holocence epoch
-quanternary period
-hadean epoch
when did modern humans evolve on Earth?
a. About 10,000 years ago
b. About 3. 2 mya
c. A bout 6 mya
d. About 4. 5 bya
URGET PLEASE HELP!!!!