secondary lymphoid organ

例句：

1. 1.The immune system is composed of several secondary lymphoid organs.
   免疫系统由几个次要淋巴器官组成。
2. 2. The research on the function of the secondary lymphoid organs has been ongoing for decades.
   对次要淋巴器官功能的研究已经持续了几十年。
3. 3. The study of the secondary lymphoid organs is essential for understanding the immune response.
   研究次要淋巴器官对于理解免疫反应至关重要。