string(256) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E4%BB%80%E4%B9%88%E6%B7%80%E7%B2%89%E5%8F%AF%E4%BB%A5%E7%94%A8%E6%9D%A5%E5%8B%BE%E8%8A%A1 => Failed to connect to 14.18.117.71 port 38133: Connection refused"
什么淀粉可以用来勾芡
