Поставьте глагол в соответствующую форму инфинитива.
1. They made him (to wait - Simple Infinitive Active) for an hour. 2. It could (to use - Simple Infinitive Passive) in colloquial English. 3. He was sad (to hurry - Perfect Infinitive Active). 4. There are a lot of problems (to solve - Simple Infinitive Passive).