Brave New World, chapters 4 and 5
1 - Why is it important for Lenina to publicly prove her unfaithfulness to Henry?
Because
at the time of brave new world there was no exact definition of fidelity, because
all the people had many couples and this is demonstrated in several parts of the book. first, it is justify in the chapter 3 on page 38, and this is the quote:
"And to tell the truth, said Lenina, I'm beginning to get just a tiny bit
bored with nothing but Henry every day".
So, It is
for this phrase that we can take at a series of debates that they don't know
the really meaning of the true love, and finally a phrase that Lenina occupies
to demonstrate its she was unfaithfulness, is occupied in the chapter 4 page 50
and it says: "Anyhow, she was publicly proving her unfaithfulness to
Henry. Fanny ought to be pleased, even though it was Bernard. So this
reflects the important of follow the rules of this society, that for me
consideration it is wrong this type of thought
2 - Is it Natural to be in a couple and raise a family in the Brave new World? Why / why not?
It's not natural,
because the social rules at that time say that this is not correct, In the contra
part they thought that the human being should have many couples and that should
not be enslaved by way of a only couple. This is reflected in the chapter
3 page 35: "Their world (the past) didn't allow them to take things
easily, didn't allow them to be sane, virtuous, happy." That is why this
question is totally related to the unfaithfulness of the world of brave new world in which
it is assumed that someone can be happy only if it is free to be with anyone, in
wherever they want and however they want.

3 - What is the meaning of "pneumatic" when it is used to describe Lenina?
The official definition is basically "full of air," but this description can be metaphorical. It seems that he wants to mean that she's busty, curvy, and all-around sexy
4 - What is "Soma" and why do people use it?
its a designer drug with no side effects can cure feelings of sadness and who use every time they want a vacation or experience negative emotions and want to escape reality and is shown according to chapter 4 page 52: "you do look glum! What do you need is a gramme of soma. Diving into his right-hand trouser-pocket.Benito produced a phial. One cubic centimeter cures ten gloomy ... but, I say! "
He was a
small man and is evidenced in the chapter 4,page 55: "I have stood eight centimeters
short of the standard Alpha height and was slender in proportion" and a
very important thing that says Bernard in this same page is that he does not
feel comfort with his identity: "I
am I, and I wish I wasn't." His physical condition it was hurting a
lot in their work, because it's made him feel uncomfortable and a he feel that
is was observed by society for being different from the others. This was
reflected in the page 55: "For gammas, deltas, and Epsilons had been to
some extent conditioned to associate corporeal prejudice in favor of size was
universal. Hence the laughter of the women to whom I have made proposals, the
practical joking of his equals among the men. The mockery made him feel an outsider".