---I hope you enjoyed the film last night. ---How on earth do you know I went to a film? I you.
The woman ________ Mr. Brown is a professor from Beijing University.
The head teacher comes to the classroom ______ to see if the students are quiet.
I’ve been playing the piano for four hours and I am ________ it.
Look, a demonstration ________ on Main Street.
What he has done has a bad effect ________ the children.