Sparks’ Crew notices that ice cream cones are pointy on the bottom. You can’t make an ice cream cone stand up by itself. The cone doesn’t balance. It wobbles and falls down. You and your child can use ...
Introduction What makes an object stay balanced? Look around you. Most of the objects in the room are probably balanced—and not on the verge of tipping over. If someone hands you an object and asks ...
一些您可能无法访问的结果已被隐去。
显示无法访问的结果