You must change the focus of the sentence from the action, or ones doing the actions, to the ones that are the "target" of the action, like this:
313. He's listened to with great interest by the students
...
316. The problem was much spoken about by them
...
320. He was laughed at by all the pupils
321. What measures will be taken by them?
...
325. Were the children given their milk by you?
326. Will I be shown the shortest way to the station by them?
327. Such things can't be done by you here
...
331. Christmas is celebrated by many people
332. I'm sure their secret will never be discovered by them
333. He was never seen in the club by us
