In a moment of whale selection, good knowledge is in your ears. Listen for 15 minutes, open the door of knowledge and lead to a quality life. More than 300 packs of in-depth knowledge in various fields: literature, history and philosophy, music and painting art, spiritual healing and other in-depth knowledge are available for you to choose and listen to. Lecturers in various fields are professional leaders, provide wonderful knowledge content, explain the profound things in simple language, and