Do you not know that every sentence has a subject, and that, if the subject were nothing, the sentence would be nonsense?

难道你不知道每一句话都有一个主语吗？那么，如果主语都不存在，句子不是就没有意义了吗？

youdao

For every subject, there are really only two things you really need to know.

对任何一个学科，都只有两件事情你需要真正的去了解。

youdao

What I also can say is that every passenger that passes security checkpoints is subject to many layers of security, as we all know, including a thorough physical screening at the checkpoint as well as other measures.

WHITEHOUSE: Press Briefing