1. A student teacher is doing that experiment.
⇒ That experiment is being done by A student teacher
2. Did you buy this dictionary two weeks ago?
⇒ Was this dictionary bought two weeks ago ?
3. Alan's knowledge about science and technology doesn't impress me.
⇒ I am not impressed by Alan's knowledge about science and technology
4. They are going to build a new school here nest year.
⇒ A new school is going to be built here next year.
5. I have used this computer for two years.
⇒ This computer has been used for two years.