Расскройте скобки и поставте глаголы в Passive Voice…

Расскройте скобки и поставте глаголы в Passive Voice 1.The rule explained by the teacher at the last lesson (to undestand) by all of us2.The poem was so beautiful that it (to learn) by everybody.3.I hope the inovitation (to accept) by everybody.4.The letter (to post) in half an hour.5.It seems to me that music (to hear) from the next room