短文中共有10处错误，每行中最多有两处。错误涉及一个单词的增加、删除或修改。

增加：在缺词处加一个漏词符号（/\），并在此符号下面写出该加的词。

删除：把多余的词用斜线（\）划掉。

修改：在错的词下划一横线，并在该词下面写出修改后的词。

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。

This morning Professor Smith, foreign teacher from Beijing University, who gave us an English lesson. All of us were deep impressed by this unforgettable lesson. The professor began the class in an amusing English story, which attracted their attention at once. He spoke slowly and clearly so that we could follow him well. Greatly inspiring, most of us took an active part in classroom activities. After class, many students were spoke highly of him. They said never before have they experienced such interesting a class. From his lesson, we realized that it is not so difficulty to learn English well if we find a good way.

每开完一个信筒（箱），都要坚持“三看”，即（）

A、看投信口

B、看箱四壁

C、看箱顶部

D、看箱底盘