认真看了一下，美国并没有禁止MCF学校的所有学生入境

The entry into the United States as a nonimmigrant of any national of the PRC seeking to enter the United States pursuant to an F or J visa to study or conduct research in the United States, except for a student seeking to pursue undergraduate study, and who either receives funding from or who currently is employed by, studies at, or conducts research at or on behalf of, or has been employed by, studied at, or conducted research at or on behalf of, an entity in the PRC that implements or supports the PRC’s “military-civil fusion strategy” is hereby suspended and limited subject to section 2 of this proclamation.

原文的意思难道不是，现在或已经在MCF学校学习研究的学生才受影响吗？换句话说，仅从字面意思理解，MCF毕业生完全不受影响。
是我理解错误吗？欢迎指正，谢谢。

是的，是你理解错误

has been不加具体时间的话就和一般过去式表达同样的意思。所以毕业生会受影响

> has been employed by, studied at

楼主完全不了解什么是完成时吗？

曾经学习过。

has studied at了解一下

完成式bdbd

是否美国的bnb公司也是对华人的房东账号进行一种注销账号比较喜欢。