不是任何其他对象的子对象的对象称为完整对象。

An object that is not a sub-object of any other object is called a complete object.

youdao

区域大小落差：一个对象的区域大小和该对象的子对象的区域大小之间的差别。

Drop in reach size: the difference between the reach size of an object and the reach size of a child of that object.

youdao

但是如果我们希望一个被删除的对象的子对象也被扔掉或者删掉，该怎么办呢？

But what if we want an object's children to be thrown away on deletion, too?

youdao