你好,翻译是：她将她的背靠着/倚着老师的桌子站着
against此处意思是：靠着,倚着
with her back against the teacher's desk是个伴随状语,用于修饰此句话中的谓语动词is standing,用以描述“她”站的状态
希望对您有用,祝您学习进步
望采纳谢谢