09. The man bought a new house last month.
A new house was bought last month by the man.
10. The woman usually buys oranges at the market but today she is buying them at the supermarket.
Oranges are usually bought at the market by the woman but today she is buying them at the supermarket.
11. The child has bought some sweets.
Some sweets have been bought by the child.
12. The secretary is buying some pencils on Internet at the moment.
Some pencils are being bought on the Internet at the moment by the secretary.
13. The teacher had bought some small gifts for the best performing pupils.
Some small gifts had been bought for the best performing pupils by the teacher.
14. Nobody was buying the products so the company went bust.
The products were not being bought (by anybody) so the company went bust.