The first textbooks ______ for teaching English as a foreign language came out in the 16th century.

—The police have caught the murderer.　　   —Yes, and he admitted ________ his boss on a rainy night seven years ago. 

______ by many well-known experts and film stars, the product was very popular at one time.

______ in London, the penniless American wandered on the pavement, ______ to find a job to make a living.

______ in a white uniform, he looks more like a cook than a doctor.