假定英语课上老师要求同桌之间交换修改作文，请你修改你同桌写的一下作文。文中共有10处语言错误，每句中最多有两处。错误涉及一个单词的增加、删除或修改。

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。

注意：1. 每处错误及其修改均仅限一词；

2. 只允许修改10处，多者（从第11处起）不计分。

Dear Mr. and Mrs. William，

I've learned that you are interested in Beijing Opera, so I've come to give you two ticket for tomorrow evening's Beijing Opera at Mei Lanfang Theater. But it's real a pity that you happened to be out. So I have to leave the tickets with this note. The  opera will be put on by some famous actors or actresses. He is well worth watching. By the way, I've read the two books you lent me, that are very interested. This week, I am busy review my lessons in order to pass the final exams. I'm afraid of that I can't go to the Opera together with you.

I hope you will have good time.

Yours，

Li Ming

儿童道德观念的发展，大致要经过3个阶段：学龄前阶段；小学阶段；（）阶段。