1. It was studying Math that she found most difficult at school.
2. It was Mary that he heard about it from.
3. It was because she was the best qualified that she got the job.
4. It was when they were both studying in London that Mike first met Jenny.
5. It was when he started speaking that I only realized who he was.
6. It was until yesterday that I heard about it.
7. It was the smell of garlic that he liked the best.
