revolving door

1. N-COUNT Some large buildings have revolving doors instead of an ordinary door. They consist of four glass doors which turn together in a circle around a vertical post. 旋转门[usu pl]

As he went through the revolving doors he felt his courage deserting him. 走过旋转门的时候，他觉得自己丧失了勇气。

2. N-COUNT When you talk about a revolving door, you mean a situation in which the employees or owners of an organization keep changing. 人员频繁更替[usu sing] [表不满]

They have accepted an offer from another firm with a busy revolving door. 他们接受了另外一家频繁换人的公司的聘用。