string(314) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E5%8F%91%E7%8E%B0%E7%94%9F%E6%B4%BB%E4%B8%AD%E7%9A%84%E7%89%A9%E7%90%86%E7%8E%B0%E8%B1%A1%2C%E5%B9%B6%E7%94%A8%E6%89%80%E5%AD%A6%E7%9F%A5%E8%AF%86%E8%A7%A3%E9%87%8A => Received HTTP code 403 from proxy after CONNECT"
发现生活中的物理现象,并用所学知识解释
