What's the difference between the old and new versions before the summer solstice?

I bought the old version and the new version.

There is no difference in feeling content.

Is to reprint the preface and introduction.

I feel that the topic is different, and the beginning is a little different.

There is also a different cover.

There is also a new version of the presentation of M. Guo's photo album and so on.

That's about it.

If there is an old version, it is not recommended to buy a new version.

If there is no LZ, you can try it.