Cultivar mixtures have been put to more attention, and for wheat, such mixtures have shown at least two advangtages over their components in pure stands: improved yield stability and reduced severity of diseases, especially that of rusts and powdery mildew.

Through the comparations to the documents both at home and abroad,the article think that judge the attribute of educational products should proceed from consumption characteristic of the education,understand according to the intension of public articles,thus judge that educational products belonging to the mixed products.