问答题
Mary finds that it is the hardest part of going back to school at her age to sit in class for a long time. Because she is not as quick as she used to be, Mrs Hanson often gets up and walks around classes to keep from getting stiff (不灵活的). At the beginning of a computer course, the other students all stood up to give her a warm welcome when she explained why she was there and what her plan was.