下文共有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。
One afternoon, while I was doing my homework, then suddenly I heard someone knocking at the door. I rose my head, looking out of the window to see who it was. A man of about 50 broad shoulders and glasses were standing on the door steps. He was tall, wearing in an old army coat. He grew a wild beard. A big black hat was pulling forward over his eyes so that it was hard to see her face clearly. His shoes were old but worn out. It was a big hole in one of his socks. He had with him a black box in one hand. Only after I took a few more closer looks at him I recognize that he was my neighbor ten years ago.
游离端缺失，可摘局部义齿修复，
作基牙，选择就位道时，模型放观测台上应（）