Need and Necessity

1) May I change the word “need” for the word “necessity” in the following sentences?
a We draw money from the account as the need arises.
b We must look after the needs of the elderly.
c Our schools meet the educational needs of every child.
d Contact our New Supermarket: a service that caters for your every need.
e There's no need for you to come if you don't want to.
f There's a growing need for new housing in many rural areas.
g We fully recognize the need to improve communications.
h Don't you ever feel the need to take a vacation?
i There's no need to shout; I'm not deaf!
j Our aim is to provide adequate food for those families in need.
k The whole house is in need of painting.
l Many of the refugees are in dire need of medical treatment.
m China has its own space technology and has no need of Russian help.

2) May I change the word “necessity” for the word “need” in the following sentences?
n A telephone is an absolute necessity for this job.
o We went to buy the basic necessities for our stay.
p Food and clothing are the bare necessities of life.
q Martin Company was faced with the necessity of firing many of its employees.
r There's no necessity to buy tickets in advance.
s The treaty is considered a diplomatic necessity.
t He was forced by necessity to steal a loaf of bread.
u The summary of his findings is, of necessity, very brief.
v Necessity is the mother of invention.
w Taxes are a regrettable necessity.
x Leave it to me - I'll do the necessary.
y The summary of his findings is, of necessity, very brief.