Isbn: 9787110086636 - 多种多样的密写信息(附光盘)/好玩的科学实验包 (1 resultados)

paperback. Condición: New. Language:Chinese.Paperback. Pub Date: 2015-09-01 Pages: 16 Publisher: Popular Science Press fun scientific experiments package a variety of secret writing information packets through pH aqueous reagent case lemon powder and baking soda solution discoloration. let 8 ~ children under 12 years of preliminary understanding of acid-base indicator in case of acid-base discoloration phenomenon in the game experience of scientific knowledge.…