string(261) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E7%AE%80%E8%BF%B0crm%E7%9A%84%E5%85%B7%E4%BD%93%E4%BD%9C%E7%94%A8%E6%98%AF%E4%BB%80%E4%B9%88 => Failed to connect to 101.89.159.206 port 38075: Connection refused"
简述crm的具体作用是什么
