hierarchy
n
system with grades of authority or status from the lowest to the highest 等级制度
She's high up in the management hierarchy. 她在管理阶层中地位很高.
There is a hierarchy in the classification of all living creatures. 一切生物均可按等级分类.
Yes. It sounded like a train that was going under my house.
是的。这响声听起来像是一列火车在从我的房子下面驶过。
Do you remember one afternoon ten years ago when I came to your house and borrowed a necklace of yours? Pierre, my husband, was working in a government office. We'd been invited to a ball at the palace so I needed to borrow some jewellery.