Ответ:

1. The postbox is emptied every day

2. The stamps are postmarked at the post office

3. The letters are sorted into the different towns

4. The mail is loaded into the train

5. The mailbabs are unloaded after their journet

6. The bags are taken to the post office

7. The letters are sorted into the different streets

8. The letters are delivered

277.

1. The postbox was emptied yesterday

2. The stamps were postmarked at the post office

3. The letters were sorted into the different towns

4. The mail was loaded into the train

5. The mailbags were unloaded after their journey

6. The bags were taken to the post office

7. The letters were sorted into the different streets

8. The letters were delivered

278.

1. The post will be emptied tomorrow

2. The stamps will be postmarked at the post office

3. The letters will be sorted into the different towns

4. The mail will be loaded into the train

5. The mailbags will be unloaded after their journey

6. The bags will be taken to the post office

7. The letters will be sorted into the different streets

8. The letters will be delivered

:)