教学目标:过程与方法:探索使一个保鲜袋发出声音的种种方法,并试着提出有关声音的问题;观察物体在发声和停止发声时的变化,概括出物体发声时的规律。科学知识:通过实际观察,建立振动的概念,知道声音是由物体振动产生的;知道摩擦、弹拨、敲击、吹气等方法可以使物体产生振动而发 Teaching Objectives: Processes and Methods: Explore ways to make a fresh-keeping bag sound and try to raise questions about the sound; observe the changes in the object as it sings and stops vocalizing, and summarizes the laws when it comes to sound. Scientific knowledge: through the actual observation, the establishment of the concept of vibration, that the sound is generated by the vibration of objects; know friction, plucked, percussion, inflatable and other methods can make the object vibration