If someone "pulls an all-nighter" for an exam, what are they doing?

Staying awake all night to study or prepare for an exam

If someone "learns the ropes," what have they done?

Gained knowledge or experience about how something works or is done

 What does the idiom "to be a teacher's pet" mean?

To be the teacher's favorite student or show favoritism 

What does it mean if someone "passes with flying colors" in their exams?

They performed exceptionally well and achieved high marks

What does the idiom "to hit the books" mean?