A． at all American universities
B． only in elementary and high schools in America
C． for bad students only
D． by some college professors

A． go to every class, no matter how he or she feels
B． go to class unless there is a good reason not to
C． stay in the dormitory and study
D． make excuses to the teacher

A． know the answer to every quiz question
B． answer only interesting questions
C． know the answer to every question the teacher asks
D． know the answers to most quiz questions but maybe not the hardest one