Module 9 FriendshipUnit 3 Language in useLanguage practiceRevision Could you explain what happened then?Can you tell me how she’s different?Could I ask if you’ve mentioned this to her?Do you know why she treats you like that?I did not know who she was.I asked her why she smiled at me that day.1. 当从句为陈述句时, 用连词 that 引导;2. 当从句为一般疑问句时, 用 if / whether (但whether可以与or not连用, if不能);3. 当从句为特殊疑问句时, 用when, where, how, why, who, what 等疑问..