题目

Read and Choose.读一读，选择适当的句子完成对话。 A. I think you like oil paintings better. B. How about you?C. He’s a great artist in the world! D. They’re both beautiful!E. So why do you like it?A. I think you like oil paintings better. B. How about you?C. He’s a great artist in the world! D. They’re both beautiful!E. So why do you like it?Sally: Kevin, look at these two pictures!Kevin: Wow! (1) ________Sally: Which one do you like, the one on the left or the one on the right?Kevin: I like both. (2) ________Sally: I like the one on the left. It’s a Chinese ink painti纳米磁性流体材料广泛应用于减震、医疗器械、声音调节等高科技领域。下图是制备纳米Fe3O4磁流体的两种流程：（1）分析流程图中的两种流程，其中______（填“流程1”、“流程2”）所有反应不涉及氧化还原反应。步骤①反应的离子方程式为____________。（2）步骤②保持50℃ 的方法是_____________。（3）步骤③中加入的H2O2电子式是_______，步骤③制备Fe3O4磁流体的化学方程式为_______。（4）流程2中FeCl3和FeCl2制备Fe3O4磁流体，理论上FeCl3和FeCl2物质的量之比为_____。己知沉淀B为四氧化三铁．步骤⑤中操作a具体的步骤是____________。（5）利用K2Cr2O7可测定Fe3O4磁流体中的Fe2+含量。若Fe3O4磁流体与K2Cr2O7充分反应消耗了0.01mol·L -1的K2Cr2O7标准溶液100mL，则磁流体中含有Fe2+的物质的量为______mol。