The reason why it is difficult for spiders to sell masks is that spiders are afraid of difficulties. In the story of "Spider Opens a Shop", when selling masks, a hippopotamus customer came. The spider thought that the horse's mouth was so big that it would be difficult to weave masks, so it felt that the masks were difficult to sell. The first time I met someone with a big mouth when selling masks, Spider was afraid of difficulties and thought it would be difficult to sell masks, so he didn't persist.