文中共有10处语言错误，要求你在错误的地方增加、删除或修改某个单词。

增加：在缺词处加一个漏词符号（∧），并在其下面写上该加的词。

删除：把多余的词用斜线（＼）划掉。

修改：在错的词下划一横线，并在该词下面写上修改后的词。

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11处起）不计分。

A boy who was cleaning the shoes in the street said to a young man passed by, “Let me clean your boots. It just spends you only a penny.” But the man refused. Then the boy told him that he will clean his boots for nothing. The man agreed, and soon one of the boot shone brightly. Then he put the other boot on the box, and the boy refused to clean it if he was paid two pence for his work. The young man refused pay anything and went away. But the well-cleaning boot made the dirty one so bad that he could not walk on. He returned back and gave the boy two pence.   

派生类构造函数的执行顺序是先执行【 】的构造函数，然后执行成员对象的构造 函数，最后执行【 】的构造函数。