voluntary muscle

例句：

1. 1. The volunteergroup is responsible for cleaning the streets afterthe storm.
   志愿者小组负责在暴风雨后清理街道。
2. 2. He decided to volunteer his time tohelp those in need.
   他决定自愿抽出时间帮助有需要的人。
3. 3. The voluntary donationwill go towards funding a new library.
   这笔自愿捐款将用于资助新图书馆的建设。