【正确答案】正确答案： Universities' Grading Systems Most American colleges and universities use the grading system of A, B, C, D and F. / A small number of colleges reject the traditional grading system. / They are organized into programs taught by teams of professors. / Students are required to do a major research project at the end of each program. / The professors write detailed evaluations of the students. / These are combined with evaluations written by the students themselves. / Most teachers would probably agree that traditional grades are sometimes unfair. / But professors at big schools say there is not enough time / to write evaluations for each student in large classes. /