互动封闭仿真课堂
1、智能交互 2、电子板书式视频教学 3、在线互动问答 4、封闭课堂启发式教学方式
随堂测试、知识梳理、易错点揭示、总结启迪智能错题本
听课中的错题能自动加入错题本,课后可方便复习及导出错题本升级服务
在线答疑、课后同类题练习、讲义下载、短信提醒(1) (和can,could,be able to连用) 有 (时间、经济等) 条件(做某事) to do
We can't afford to pay such a price.
afford n. / pron. (出得起;买得起等)
They donot consider whether they can afford it or not.
(2) 经得起 (做某事或发生某事) (多 to do)
He could not afford to lose his fortune entirely.