Answer:
b
Explanation:
a semi permeable membrane requires no energy since it allows safe passage of molecules from low to high think of it like a tea bag it has a high concentration and the low concentration is the hot water.
I hope it helps
It implants itself to the walls of the uterus (endometrium) by umbilical cord.
The answer is most likely the last option.
An eon is 1.05 billion years and an era is 350 million years