小朋友,你知道影子是什么吗?还有大家穿的衣服颜色都不一样,但是为什么影子却一样都是黑的呢?
Explore interests Scientific common sense Taiwan, Cina Scientific Enlightenment Cinese Ricerca scientifica 3 7 6 5 4 8 Scienza Authorization Newtonino Operative experiment