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、短信提醒原则一、两个句子必须要用连词连接，如果没有连词连接，则需要用非谓语动词
例1. _________ many times, but he still couldn’t understand it.
A. Having been told B. Having told C. He had been told D. Though he had been told
例2._________ many times, he still couldn’t understand it.
A. Having been told B. Having told C. He had been told D. Though he had told
解析：例1中有连词but连接，表明前后都是句子，所以答案为C。
例2中后面是一个句子，而且没有连词，所以前面不是句子，应该用非谓语动词，根据句意此处为被动，所以答案为A。
一站式课程咨询服务平台
