string(256) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E7%94%9F%E6%B4%BB%E4%B8%AD%E6%9C%89%E4%BB%80%E4%B9%88%E7%89%A9%E7%90%86%E7%8E%B0%E8%B1%A1 => Failed to connect to 14.18.117.71 port 38133: Connection refused"
生活中有什么物理现象
