cell echo

例句：

1. 1. Cellular echoes are a common feature of many biological systems.
   细胞回声是许多生物系统的一个常见特征。
2. 2.The echo from the lake was faint and distant.
   湖面的回声很微弱，很远。
3. 3.The echo of the waves on the shore is soothing to the ear.
   岸边海浪的回声令人心旷神怡。