1) This letter was received after his depature.
2) Have you ever been attacked by dogs?
3) Honey is gathered from flowers by bees.
4) The ship was driven against the rock by the storm. 
5) Who(m) was the circulation of blood discovered by? 
6) Delicious fruit ice cream is being sold there now.
7) We were shown the way out of the wood...
The way out of the wood was shown to us by the old man.
8) Some interesting work was offered to her. 
She was offered some interesting work by them.
9) New medicine was  prescribed to her by the doctor.
She was prescribed new medicine by the doctor.
10) He is often spoken about.( by them.) 
11) This funny animal was  laughed at by everybody.
12) I have been looked for by them the whole morning.
13)  Strict discipline will be insised on.
14) Three foreign languages are taught by them at this school.