How should the bolded words in the sentence be contracted? you must not tell everyone!

must'not
mustnt'
m'stn’t
mustn’t

The correct contraction is mustn't. When you  think in contractions you have to bear in mind that the verb or auxiliary is intact, e.g. doesn't ,shouldn't, isn't, don't, can't.

the answer is mary made mudpies on monday.

remember alliteration is the occurrence of the same letter or sound at the beginning of adjacent or closely connected words.  

the purpose in this excerpt is that you should never do things like that because according to the bible, if you have more than one wife it's wrong and a huge sin. i hope this .