You must concentrate _____ your study not on your clothes.
--- you the cat?---Yes, I have. ---When you it? ---Ten minutes ago.
We need friends to ____, or we will feel ____.
Because of Project Hope,_______children have better lives.
The little boy ____ by the big one this morning.
I Mr. Black is strongly _______keeping animals in the zoo,because he thinks animals should also have the right to enjoy freedom.