增加：在缺词处加一个漏字符号（∧），并在其下面写出该加的词。
删除：把多余的词用斜线（╲）划掉。
修改：把需要修改的词用横线（__）画出，并在下面写出正确的词。
Wang Mei and her classmates is always helping others every day. Last Sunday they went to a nurse home and did some voluntary work When they arrived, they were all warm welcomed. They presented the old people with flowers and fruit. Then, they began work at once, clean the windows and sweeping the floor. With everything doing they sat in the yard reading newspapers to an old. When it was time for the volunteer to leave, the manager praised and thanked for them. They were very happy because that they did really brought joy to others. From their experience, I've learned that helping others is a great virtue.
