1. This sentence is more difficult than the first one. 2. He didn't know why I failed the exam. 3. Would you mind my watching television here? 4. Shaihang is one of the biggest cities around the world. 5. It's said that he spent a lot of time playing socer. 1. This sentence is more difficult than the first one. 2. He didn't know why I failed the exam. 3. Would you mind my watching television here? 4. Shaihang is one of the biggest cities around the world. 5. It's said that he spent a lot of time playing socer.