string(267) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E5%87%80%E5%88%A9%E6%B6%A6%E7%9A%84%E8%AE%A1%E7%AE%97%E8%BF%87%E7%A8%8B%E6%98%AF%E4%BB%80%E4%B9%88 => Failed to connect to 101.89.117.144 port 38017: Connection refused"
净利润的计算过程是什么
