中骨的

例句：

1. 1. The center of the city is bustling with activity.
   市中心繁忙活跃。
2. 2. The middle school students are preparing for the exams.
   中学学生正在准备考试。
3. 3. The middle aged man is looking for a new job.
   中年男子在寻找新工作。