sit down
1．sit on a seat or resting place坐下
After the gym class Jim was tired and was glad to sit down and rest．体育课结束后，吉姆很累，因此很高兴能坐下来休息。
2．sit on the ground to express opposition静坐反对
All the students sat down and refused to leave the building．所有的学生都静坐，拒绝离开大楼。
3．suffer without protest or complaint逆来顺受
I couldn't sit down any longer．我再也无法忍受下去了。