Let p, q, r, and s denote the following propositions: p denotes "You passed CS2233" q denotes "You passed CS3333" r denotes "You can register for CS3343" s denotes "You understand boolean algebra" Using p, q, and r construct compound propositions which represent the fol- lowing English sentences: (1) You haven't passed CS2233 but you understand boolean algebra. (2) You can't register for CS3343 only if you haven't passed both CS2233 and CS3333 (3) If you can register for CS3343 then you have passed CS2233 and you understand boolean algerbra if you passed CS2233