（2）若不含空白，这篇短文共有多少个字符？
（3）统计这篇短文用了多少个单词“to”。
（4）将这篇短文内所有大写字母改成小写，并将更改后的短文写到文本文件”joke.txt” 里。
There was an American couple who had no children, so they wanted to adopt a child. Finally, an orphanage contacted them, saying, "We have a baby for adoption.It's a Russian orphan." The couple was delighted and went to bring the baby home.
On the way home, they stopped by a university to enroll in a Russian course. "Why do you want to learn Russian? The English that we speak is a very good language," the university secretary asked."Well, we just adopted a Russian baby. When he begins to speak Russian in a few years, we are afraid that we might not be able to understand him," the couple replied.
