The Inca used those metals to decorate their palaces and had silverware, cups and dishes made of them.
Of course, only royalty had that.
A student buries an ice cube in a pan of dirt and observes the dirt as the ice cube melts. This activity is a model of the formation of a kettle.
The Panama Canal because it makes the most money and is the most important out of all the four.
The Prime Meridian marks zero degrees longitude. Without it, the other degrees of longitude cannot be measured.
