Noun:

1. a stomach exercise in which a person sits up from a supine position without using the arms for leverage

situn.原地；就地；在原处；在施工现场；在原位置sitv.坐；栖息；使就座n.坐；栖息Sitodiplosis mosellana麦红吸浆虫sitting in an armchair坐在扶手椅里sit back from the road座落在离大路有一段距离的地方sitting-hen mushroom贝叶多孔菌sitting comfortability坐姿舒适性sit loose to something不重视某事sitting on the veranda坐在走廊处.sit through the speech不得不听完演说Sitobion avenae Fab.麦长管蚜sit for one's portrait

sit up坐直； 坐起来； 迟睡； 熬夜

sit up withadj.陪夜

bent-knee sit-upph.

jackknife sit-up两头翘

sit up late深夜不睡

Sit up straight!坐直！

sit up and take nourishment病好了,复原了

make someone sit up使某人担任困难的工作

sit up and take noticevi.突然注意起来