string(256) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E7%94%9F%E7%B2%89%E5%92%8C%E6%B7%80%E7%B2%89%E7%9A%84%E5%8C%BA%E5%88%AB%E7%94%A8%E9%80%94 => Failed to connect to 61.171.74.35 port 38041: Connection refused"
生粉和淀粉的区别用途
