---Excuse me, how can I find useful information on the Internet?--- ________ the information you need, type in the keywords and then lots of websites will appear.

—This pair of shoes _________really big for me. —Why not try another _________?

Do you enjoy _______ football? I hear there will be a football match tomorrow.

The thief was noticed _____the office building by the back door on the screen.

Mr. Wu came into the  classroom ,         a book in his hand.