PLZ HELP ME!!!!
Which era does the rock of the Canadian Shield date back to?
a Precambrian
b Cenozoic
c Mesozoic
d Paleozoic

In what era did reptiles become dominant?


a Paleozoic


b Mesozoic


c Precambrian


d Cenozoic
What period of the Paleozoic era is known as the "age of fishes"?

Permian


Siluarian


Pennsylvanian


Devonian
What period of the Mesozoic era did dinosaurs first appear?


Jurassic


Devonian


Cretaceous


Triassic
In what era did modern man first appear?


Mesozoic


Precambrian


Paleozoic


Cenozoic