1. the room (clean) yesterday. 2. new houses (build) in our city every year. 3. the book of this writer (publish) in a month. 4. the trees (whitewash) by our pupils every spring. 5. tea (grow) in ceylon and india. 6. america (not/discover) by james cook. it (discover) by christopher columbus. 7. pizza (deliver) in half an hour. 8. thousands of new cars (produce) at this plant every year. 9. ink (use) for writing many years ago. 10. some new technologies (introduce) to the industrial companies at the end of the following month.
