1. By the time Ben got there, everyone had left. The preposition "by" is used to indicate the time or state at which something happens. In this sentence, it is used to show that everyone had left before Ben arrived. 2. The police asked Alice what she was doing at the time of the theft. The preposition "at" is used to indicate a specific time or point. In this sentence, it is used to show the specific time when the theft occurred. 3. Susan crashed into a tree yesterday. Fortunately, only the car was damaged. The preposition "into" is used to indicate movement or direction towards the inside of something. In this sentence, it is used to show that Susan's car collided with a tree. 4. We tied up the burglar and called the police. The phrasal verb "tie up" means to restrain or secure someone with ropes or other restraints. In this sentence, it is used to show that the burglar was restrained or captured. 5. John threw my backpack in the middle of the road and a car ran over it. The preposition "over" is used to indicate movement or direction on top of something. In this sentence, it is used to show that a car passed over or ran on top of the backpack. 6. Charlie and Carla set out on their journey two weeks ago. The phrasal verb "set out" means to begin a journey or trip. In this sentence, it is used to show that Charlie and Carla started their journey two weeks ago.