back echo reflection

例句：

1. 1.The sound of the waves back echoing off the shore was soothing.
   海浪声在岸边回荡，令人感到宁静。
2. 2.The artist's use of light and shadow to create a sense of depth in the painting is truly remarkable.
   艺术家利用光线和阴影在画作中创造出深度感，真是了不起。
3. 3. The teacher's explanation of the concept behind the experiment was clear and easy to understand.
   老师对实验背后的原理解释得非常清楚，易于理解。