How can I get a letter of recommendation?

<p>I'm in my senior year at the University of Arizona, but I'm going to graduate in December 2014. I'm planning on studying abroad in Australia during the Spring semester, but I need a letter of recommendation from one my teachers as part of the application. Problem is, the one teacher that I was actually close with left the school after the most recent Spring semester, and she hasn't answered any of my emails. I've never really gone to any other professor's office hours, so do you think I can still get someone to write me a letter? I took this other class on bioethics last spring with a different professor and got an A in it, but I didn't really interact with him too much. Should I still go ask him?</p>