Sa Beining: The relationship between aperture and shutter, Bai Jingting actually answered relatives.

Don't laugh at people about this, because they are like mountains. After all, people are just actors and still very young. Just like you ask an old historian a simple physical formula that middle school students all know, maybe the old man can't answer it. On the contrary, if an old historian asks a simple historical question, an old physicist may not be able to answer it.