问题的提出学习了声音的知识以后,小明对弦乐器的发声情况进行了观察,发现弦乐器发声的音调与弦的性质有着密切的关系,于是提出:弦乐器的音调与什么因素有关呢?猜想通过观察,小明发现:小提琴、吉他等弦乐器由几根弦组成,弦的粗细各不相同,由此猜想:①弦乐器的音调可能与弦的粗细有关。小明还发现:在演奏时,演奏人员还经常调节弦的松紧程度,由此猜想:② Question raised After learning the sound of knowledge, Xiao Ming observed the sound of the stringed instrument was observed and found that the tone of the stringed instrument sound and the nature of the string has a close relationship, then put forward: the tone of the stringed instrument and what factors? Conjecture by observation, Xiao Ming found: violin, guitar and other stringed instruments composed of a few strings, the thickness of the strings vary, thus conjecture: ① stringed instruments may be related to the pitch and the thickness of the string. Xiao Ming also found: playing, the performer often adjust the tightness of the string, which guess: ②