string(274) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E4%BA%8C%E5%BB%BA%E5%AE%9D%E8%93%9D%E4%B9%A6%E5%8F%AF%E4%BB%A5%E4%BB%A3%E6%9B%BF%E6%95%99%E6%9D%90%E5%90%97 => Failed to connect to 14.18.117.71 port 38093: Connection refused"
二建宝蓝书可以代替教材吗
