string(245) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E5%A4%8D%E6%95%B0%E4%B9%98%E6%B3%95%E6%80%8E%E4%B9%88%E7%AE%97%E6%AF%94%E5%A6%82-36%C3%97-1%2F4 => Received HTTP code 403 from proxy after CONNECT"
复数乘法怎么算比如-36×-1/4
