string(342) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E8%BF%90%E7%94%A8%E6%9C%97%E6%A0%BC%E7%B3%BB%E6%95%B0%E6%B3%95%E8%BF%9B%E8%A1%8C%E6%8A%95%E8%B5%84%E4%BC%B0%E7%AE%97%2C%E5%85%B6%E8%AE%A1%E7%AE%97%E5%9F%BA%E6%95%B0%E4%B8%BA => Failed to connect to 101.89.117.144 port 38208: Connection refused"
运用朗格系数法进行投资估算,其计算基数为
