The computer sends cactus (which can decompose toxic substances in the air and absorb electromagnetic radiation); Sports-sports equipment &; CD-ROM books, membership cards of sports fitness centers, etc. Music-musical instruments (such as harmonica), music albums &; Famous (&; Taste) piano music; Art sketch clips and other appliances &; Famous paintings; History-interesting history (such as DIY photos of teachers and students' life and memories of historical chronicles), ancient civilizations, unsolved mysteries and other books and CDs; Geography-Neolithic Art&; Three-dimensional geographical map of the area (for teaching); Creatures-birds are equal; Help yourself to the main course! Mathematics teaching theory of purchasable mathematics.