Sarah was not an early riser. But what made the annoying early morning hours bearable was the comforting smell of fresh coffee floating in the air. Her favorite coffee shop was just a few minutes away from her apartment.

One sunny morning, Sarah rushed to get dressed. Having a job interview, she felt anxious, afraid to be late. She grabbed her car key, dashed out of the door and made her way to her familiar coffee shop as usual. As she joined the line of cars at the drive through, the smell of roasted coffee beans and the thought of the first taste of coffee were her little daily luxury. The line inched forward, and soon, Sarah found herself at the drive-through window. She reached for her purse to pay, but before she could hand over her credit card, the coffee shop assistant smiled and said, "Your coffee has been covered by the car ahead of you." Sarah was taken aback. "Really?" she asked, feeling astonished and grateful. The assistant nodded. The unexpected act of kindness put a smile on her face, making her upcoming interview feel a little relaxing.

As she exited the drive-through, Sarah glanced in her rear view mirror (后视镜) at the next car approaching the coffee shop window. An idea began to come into her mind. Maybe she could do the same and brighten someone else's morning. She decided to return to the coffee shop. Inside, she approached the cashier and said, "I'd like to pay for the coffee of the person in the car behind me." The assistant smiled and nodded again.

As Sarah eventually left the coffee shop, Sarah couldn't help but wonder how the next driver would react. A wave of satisfaction washed over Sarah as she witnessed the continuation of the coffee chain. She knew she had just initiated a chain of generosity and kindness.