string(204) "get document error:https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E5%B1%9E%E4%BA%8EB2B%E7%9A%84%E5%B9%B3%E5%8F%B0%E6%9C%89 => Connection timed out after 30000 milliseconds"
属于B2B的平台有网!