string(258) "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%E7%9A%84%E5%88%9D%E4%B8%AD%E7%89%A9%E7%90%86%E7%9F%A5%E8%AF%86 => Failed to connect to 125.88.227.171 port 38114: Connection refused"
生活中的初中物理知识
