Today, there is a thing whose key lies in the "Glycolic Acid Percent". The characteristics and functions of this thing all revolve around the "Glycolic Acid Percent". "Glycolic Acid Percent" is about its essence and is the core direction for exploring this thing. Among all the changes and uses, the "Glycolic Acid Percent" runs through it all the time, like a pearl in a series of threads, which is the key to understanding the mystery of this thing. Only then can we understand its details.