hostloc，影子的形成因素有哪些？
形成因素等价于影子的产生条件
最简单就是光沿着直线传播这一初中物理知识
形成条件有三
1.能够遮挡住光的物体（不能是透明的）
2.能够投射出影子的地方
3.当然是光咯
三个条件缺一不可，完全具备三个基本条件才会产生影子哦。留下一个参考视频的链接https://m.baidu.com/sf?pd=video_page&nid=327550947982360421&sign=5915128401980833697&word=%E5%BD%B1%E5%AD%90%E5%BD%A2%E6%88%90%E7%9A%84%E6%9D%A1%E4%BB%B6%E6%98%AF%E4%BB%80%E4%B9%88&oword=%E5%BD%B1%E5%AD%90%E5%BD%A2%E6%88%90%E7%9A%84%E6%9D%A1%E4%BB%B6%E6%98%AF%E4%BB%80%E4%B9%88&title=%E5%BD%B1%E5%AD%90%E7%9A%84%E5%BD%A2%E6%88%90%E6%9D%A1%E4%BB%B6&atn=index&alr=1&openapi=1&resource_id=5052&frsrcid=4185&frsrcid=4185&cambrian_id=1612732424718028&sp=0&ext=%7B%22src%22%3A%22https%3A%5C%2F%5C%2Fvdse.bdstatic.com%5C%2F%5C%2Fe04e64c5aa5d1fe9db0f5117af927479.mp4%3Fauthorization%3Dbce-auth-v1%252F40f207e648424f47b2e3dfbb1014b1a5%252F2020-03-27T18%253A25%253A04Z%252F-1%252Fhost%252F2264c3133a41c9757a824d98f69d5d8d8dac1aed636d91369d94e352f06a39cd%22%2C%22loc%22%3A%22http%3A%5C%2F%5C%2Fv.qq.com%5C%2Fx%5C%2Fpage%5C%2Fi08280twzc7.html%22%2C%22log_loc%22%3A%22http%3A%5C%2F%5C%2Fv.qq.com%5C%2Fx%5C%2Fpage%5C%2Fi08280twzc7.html%22%2C%22duration%22%3A%2224%22%2C%22poster%22%3A%22http%253A%252F%252Fvdposter
