Question

How can supplies of metals such as copper and aluminum remain healthy even though there is a dwindling amount in the earth's crust?

Answer 1

They remain healthy in number because these metals are recyclable

Answer 2

Answer: The supply of metal such as copper and aluminium remain healthy even though there is a dwindling amount in the earth's crust. The supply of metals like aluminium and copper can be recycled.

The metals can be recycled inside the earth and hence, its supply remains healthy throughout all the time.

The metals are recycled and the recycled metals are used again so its supply is healthy.