I used to going to the countryside to draw animals and plants. One day I was walking across a field look for rabbits to draw. Losing in thought, I hadn’t noticed a bull to running towards me. About 100 meters ahead was a tree under that I would sit and draw. Suddenly, I heard the noise behind me. I turned and saw the bull. Knowing a bull can run more faster than a man, I quickly reached the tree and climb up. From there I saw the bull kicking my food bag by its feet. It kept done this for 15 minutes and moved away. But I was quite nervous in the tree.

最近，上海建成了我国第一条磁悬浮铁路．磁悬浮的核心技术是利用超导体的反磁性．高温超导物质（Y₂Ba₄Cu₆O₁₃）是以YmOn、BaCO₃和CuO为原料，经研磨烧结合成（此过程中所有元素的化合价均不变）．

（1）高温超导物质（Y₂Ba₄Cu₆O₁₃）由 ______种元素组成，其中Y呈 ______价，YmOn的化学式是 ______．

（2）在合成该高温超导物质的同时，还生成了一种物质，该物质是 ______．