Question 9 (3 points)
When did Cyanobacteria appear on Earth?
Ordovician period
Silurian period
Permian period
O Precambrian period

Precambrian period

Step-by-step explanation:

Since the Great oxidation period = 2.4 Billion years ago era = Precambrian period.

Micro-fossils attributed to cyanobacteria are abundant during the Proterozoic that came later 2,5 billion years ago and ended 540 million years ago,

the answer is b.

step-by-step explanation:

identity property is where 0+whatever number=whatever number. basically 0+ a number.

"exterior angles = 360 / number of sides.

60 = 360 / sides

sides = 360 / 60

sides = 6"