string(234) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=b2b%E6%98%AF%E6%80%8E%E6%A0%B7%E4%B8%80%E7%A7%8D%E6%A8%A1%E5%BC%8F => Failed to connect to 101.89.159.206 port 38075: Connection refused"
b2b是怎样一种模式
