NU has a mandatory curve that applies only to classes with more than 40 students. So essentially, I think everyone gets between an A+ and an A- in every class after the first year? Who knows, guess I'll find out in a year.
3-7% of the class must get an A+
As far as I know, professors do not give any grade lower than a B- under any circumstances. To graduate with highest honors you need a 4.20GPA; high honors, 3.97; honors, 3.65.