string(233) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E7%AE%80%E8%BF%B03d%E7%94%B5%E5%BD%B1%E7%9A%84%E5%8E%9F%E7%90%86 => Failed to connect to 101.89.143.195 port 38205: Connection refused"
简述3d电影的原理
