题目

O. Henry was a pen name used by an American writer of shortstories. His real name was William Sydney Porter. He was born in North Carolina in 1862. As a young boy he lived an exciting life. Hedid not go to school for very long, but he managed to teach himselfeverything he needed to know. When he was about 20 years old, O. Henry wentto Texas,where he tried different jobs. He first worked on a newspaper, and then had ajob in a bank, when some money went missing from the bank. O. Henry wasbelieved to have stolen it. Because of that, he was sent to prison. Duringthe three years in prison, he learn如图所示，S是发光点，S'是S通过凸透镜所成的像．画出入射光线SP的折射光线．