Emigrated means they exited so due to the high amounts of pollution all the animals left which cause a population decrease
The divergent plate boundaries
A. Polysaccharide, this is because polysaccharides have cellulose which make the grass stand up.
not really familiar with all this but I think 1. Relative dating is where they estimate or relatively guess around how old it is so you could just put something like "an estimate of the age" or something
