Mary is tired of learning because she is_____ to do better than she can, both at school and at home. 

The elderly should _________ politely. Also, they must ___________ well.

It is true that knowledge_____ rather than being taught. 

---I want to teach in this area．---Well．teachers         very much here．

—Did the book provide the information you need? —Yes. But ________ it, I had to read the whole book.