1) The documents are printed. The documents were printed.
2) The window is opened. The window was opened.
3) The shoes are bought. The shoes were bought.
4) The car is washed. The car was washed.
5) The litter is thrown away. The litter was thrown away.
6) The letter is sent. The letter was sent.
7) The book is not read. The book was not read.
8) The songs are not sung. The songs were not sung.
9) The food is not eaten. The food was not eaten.
10) The shop is not closed. The shop was not closed.