The note that was stuck in the book for a while was always missing when I opened the heavy book again, as if the note had sunk into the vast ocean, which was very distressing. But then I thought about it, wouldn’t it be nice if I hid my pocket money in it so that even if the book is opened it would not be easily discovered? As the saying goes, "The most dangerous place is the safest place." Put such a money-hiding book on the bookshelf. If anyone wants to know where the money has gone, let him find it. But when you want to use it, it takes a while...
