世界最长河流是哪条河网!
string(257) "get document error:https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E4%B8%96%E7%95%8C%E6%9C%80%E9%95%BF%E6%B2%B3%E6%B5%81%E6%98%AF%E5%93%AA%E6%9D%A1%E6%B2%B3 => Failed to connect to 101.91.112.32 port 38195: Connection refused"
世界最长河流是哪条河网!