English dilemma..

I was doing my book report when I came across a language dilemma..

I would appreciate it if someone could help me out..

Scenario:
I want to write.. Why shouldn't they?
But in reports, it is prohibited to write abbreviations.
So by right, my sentence should read.. Why should not they?

So weird..

And ya.. I've rephrased by sentence..

Hmm.. should't waste my mugging time in the library.

Back to work..