用所给词语填空。

1. He didn't feel quite well,                (或许)

2. ______ (也许) he hasn't left the train yet , and we can still find him.  

3. Don't worry , the news                (可能不) be true

4. —Why doesn't he come yet? 

    —I don't know. He_______ (或许不) come today.  

5. My mother was ill , so I     _____ (不得不) take care of her today