repeated levelling

例句：

1. 1. The teacher explained the lesson repeatedly to ensure everyone understood.
   老师反复解释课程以确保每个人都理解。
2. 2. The patient had a repeated cough that persisted for days.
   病人反复咳嗽，持续了几天。
3. 3. The researcher conducted repeated experiments to gather more data.
   研究者进行了多次实验以收集更多数据。