Absences not approved include meetings with advisors or taking make-up tests for another class. You must schedule such meeting during your free time. If you are late, you are absent. If you leave the classroom before the end of the period, you are absent. Neither of these behaviors is conductive to academic success.
Preparation includes study of topics discussed earlier and completion of the homework assignment.
Studytime and homework should take up to 2 hours of time for each hour spent in class. You need to take whatever steps necessary to ready yourself for the class each day. Expecitng to complete all necessary work in the classroom with no outside preparatin is unrealistic and will usually lead to failure.