About the urdf script not work

I copied the gurdy.urdf Document, and write a launch script.but here is nothing be showed.what should I do?

Hello @weizhenyu1556,
Can you give us a bit more information? What chapter are you in? What commanda did you execute? How does your launch file look like?

Same thing happening to me, all above requested info is in this image

Thanks for your help!

What do you expect to happen and what actually happens? I see no errors.