Выберите соответствующую форму инфинитива. 1. It is forbidden (to smoke, smoke) here. 2. She made the driver (to stop, stop) the car. 3. When I was a child my parents didn’t let me (to eat, eat) ice cream. 4. In the forest we saw some birds (to build. build) their nests. 5. I can often (to hear, hear) her singing.

Я не знаю еще, что такое инфинитивы, но правильно будет:
1. to smoke
2. stop
3. building
4. hear