--- Steve, don’t do eye exercises with your eyes _________.--- Sorry, I won’t.

 ---Is this book Betty's? ----Yes , it's ________. 

—________ will your father be back?—My father will be back in half an hour.

 I didn’t know the place very _______before. But now I’ve known _____about it.

---_______ is it from your home to school?---It’s three miles.