В предложенном тексте есть несколько пропусков, которые нужно заполнить, чтобы история была логичной и грамматически верной. Рассмотрим каждый пропуск:
Ответ: When Sam back home, he saw a car accident. Two cars at the pedestrian crossing. Sam was just about to cross it when he saw a red car. It was too fast, and the driver didn't manage to stop. He hit a black car which was standing at the front. Luckily, nobody got hurt. The drivers called the police. When the police came, they started to question pedestrians and other drivers. Sam had to answer several questions too. While he was answering, the driver of the red car left the scene of the accident. The police quickly found the criminal and arrested him.