Correct the mistakes in four of the following sentences.

1. I telephoned to my father to tell him I'd be late.
2. Jessica married with an owner of a big IT company.
3. When we entered the office we saw a pair of thieves stealing our computers.
4. He was operated on by one of the top surgeons.
5. He borrowed me some money.
6. We don't approve social networking sites.
7. He spends a lot of time surfing the Net.