<em>Hi there, I come in behalf of jcherry99,</em>
So, first question -
This shouldn't be that much of an issue, since we have the text to help us out, but I'll try breaking it up into more simpler words:
The placenta is incide the uterus, where the baby starts forming. As you might already know, babies do not eat while they're inside woman's bellies:
So how do they feed?
They feed throught the umbilical cord.
So why is the placenta there? Why would the baby want anything apart from food?
The placenta, instead of trading food with the baby, regulates temperature, supplies it with nutrients, exchanges gas with the mother (which the mother later exchanges with the environment) and gets rid of waste.
And, food is not everything for a baby that is in the urge of developing complex muscles, bones, etc.
Second "question" -
I do not actually know what I'm supposed to do, since there is no question. But I can tell you this - the information contained in part B is correct:
The amnioic sac provides babies with a liquid which allows him to move freely in the uterus, which is very helpful. But, note that he doesn't start moving randomly, he is always in a fetus or similar-to-fetus position.
Hope it helped,
BioTeacher101
are in 
we can simply divide 
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