string(286) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=cad%E6%96%87%E4%BB%B6%E7%89%B9%E5%88%AB%E5%A4%A7%E5%A6%82%E4%BD%95%E6%B8%85%E7%90%86%E5%86%85%E5%AD%98%E7%A9%BA%E9%97%B4 => Failed to connect to 14.18.117.71 port 38041: Connection refused"
cad文件特别大如何清理内存空间
