1. the postbox (to empty) every day. 2. the stamps (to postmark) at the post office. 3. the letters (to sort) into the different towns. 4. the mail (to load) into the train. 5. the mailbag (to unload) after their journey. 6. the bags (to take) to the post office. 7. the postbox (to empty) yesterday. 8. my question (to answer) yesterday. 9. hockey (to play) in winter. 10. many houses ( to burn) during the great fire of london. 11. flowers (to sell) in shops and in the streets. 12. st. petersburg (to found) in 1703. 13. many houses (to build) in our town every year. 14. this text (to translate) at the last lesson. 15. we ( to invite) to a concert last saturday. 16. i (to give) a very interesting book at the library last friday. 17. these trees (to plant) last autumn. 18. this bone (to give) to my dog tomorrow. 19. mushrooms (to gather) in autumn. 20. this work (to do ) tomorrow. !