It is very discrepant

As I mentioned, I have a part time job at cram school, but recently, I am thinking about how to balance my efficiency and conscience about this job.

The problem is that I have to do too many things in one hour. I have to teach students vocabularies, give them a quiz, and explain the questions the students don’t understand in exercise paper. Otherwise I have to keep them in order. It is not difficult for me, of course, but it really has taken me too much time within an hour. However, what I really want to do is teach them more correlatable usages about vocabularies which they just learned, like some equivalents or phrases about the vocabularies, but it always not enough time. How should I do, they only have less than a year to prepare their entrance examination for senior high school. How can I give up their future just because of the limitation of time? It is really a discrepant situation struggled in my mind. How should I do?