"sit"的反义词是 stand。例如：
1. She was sitting on the couch, and when she saw me, she stood up.（她坐在沙发上，当我看到她时，她站了起来。）
2. They were sitting at the table, but when the bell rang, they all stood up to greet the guests.（他们坐在桌子旁，但当铃声响起时，他们都站起来迎接客人。）