midterm studying prioritization?

So right now midterms are in about 2 weeks, and I am behind on studying because I bummed out during winter break. Anyways, I was wondering if it would be wise to prioritize more of my time on classes that I really need the points in and would admissions officers care about a low midterm exam?. An example would be my two A+ quarter grades in Modern World History, I could get a C and still end with an A, but my school shows midterm and final exam grades, so would this affect their opinion on me as being lazy or slacking?