Exams, grades, and marks should be abolished because children' s progress should only be assessed by______.

A．By making mistakes and having them pointed out by others.
B．By having their mistakes corrected.
C．By noticing their problems and making changes.
D．By listening to explanations from skilled peopl

A．providing students with help when necessary
B．finding out students' mistakes and correcting them
C．teaching students the essential knowledge that they will need in their future life
D．telling students the correct answers