This is the third part of your benchmark review
Organisms became separated and new species foo
There was less oxygen, so they died
Organisms couldn't survive in the oceans
Organisms didn't change at all
Volcanoes erupting
Meteors making explosions
A bomb exploding
Sudden appearance of various animals
Small amounts of water and nitrogen
No ozone and small amounts of oxygen
More oxygen and other chemicals than today
It was really windy and cloudy
Increased the diversity of mammals
Made more plants for mammals to eat
The climate changed and mammals liked the new climate
There were more fish to eat for mammals
Ovaries
Prostate
Testes
Urethra
Egg cells are released from the ovary
The shedding of the lining of the uterus
The process of a sperm fertilizing an egg
When a sperm has fertilized an egg
Sperm gets made
Hormones are affected by sperm
Eggs are released by the ovaries
Eggs may be fertilized by sperm