He fell asleep with a book ___________ open on his knees.

-- The fish            nice. Your mother is a great cook.-- Really? Try some, and you will like it more.

The environment is becoming worse and worse. I think we should do something to ____ people ____ cutting the trees in order to protect the earth.

We are looking forward to ____ my grandparents soon. 

The teachers ________ us _______ their children.