Read the following sentences:
Bart set his alarm. For once he made it to class on time.
Which revision below is a compound-complex sentence?
Since Bart set his alarm, for once he made it to class on time.
Bart made it to class on time, because he set his alarm.
Bart set his alarm, and for once he made it to class on time.
Since Bart made sure that he set his alarm, he made it to class on time for once.