Christianity Question

Christianity Question

This is a question that came in my mind a few days ago and has kept on being in my mind...

I have no offence with Christian people and hope the following wont offend any of you!

It is believed to be said that God created the world, all the living animals, human beings, etc in seven days.

Ok, Adam and eve are the first ever humans to be on this planet...
This means they are supposed to be living with dinosoars in the prehistoric era billions of years ago...

They had children... of which one (forgot the name) sacrificed a sheep on some hill...

this doesn't make sense, since there aren't any sheep during prehistoric era...
that means sacrificing sheep can only be less than one million years...

this big time gap doesn't make much sense to me...

Again, i have no offence against any religion, i'm just really curious and would be glad if anyone could help me!
Thanks!