The reproductive system of a male mammal provides (1) support for the internal development of the embryo
(2) materials through the placenta
(3) a means for the delivery of sperm cells
(4) the ovaries for egg production

Which statements explains what the fossil records indicates? check all that apply. a) earth is 4.5 billion years old b) many organisms have become extinct c) mammals have always existed on earth d) mass extinctions have occurred several times on earth e) the amount of water on earth has decreased over time?