LOR concern

<p>I'm in 3rd year and I'll apply next year. In the past 3 years, there was no single prof I've consistently stayed in touch with for more than a semester (while taking their course), though I frequently visited their office hours while taking their courses. Ideally one should ask a prof who knows him/her really well over a long period of time with a relationship history of like 2+ years, but should I be worried that I'm far from ideal? I still have a year left so I can spend this last year trying to find profs who will write me LORs. My LOR writers will probably be upper-level profs who know me for less than a year. But would it be still possible for me to get great LORs?</p>