题目

Stan Lee, who helped create Spiderman, the X-Men, Iron Man, the Incredible Hulk (绿巨人), Black Panther (黑豹), and many other comic book heroes, has died at the age of 95. Stanley Martin Lieber was born in 1922. When he was just 17, he got a job at a company that made comic books. As a writer, he started using the name—Stan Lee Ⅱ (which sounded like his first name, Stanley). He wrote his first Captain America story in 1941. It was very popular. Before he was 19, he was responsible for all writing for the company, which became Marvel Comics (漫威漫画公司) in the1960s. At the tim两圆相切，圆心距为5，其中一个圆的半径为4，则另一个圆的半径为    ．