The sources of metal used are very difficult to determine.

We don't often see metal used as a light, reflective skin.

They do not use metal for any purpose other than ornaments.

I have and, believe me, there's nothing quite so hard to make as a strong fishhook if you can't use metal.

God might just as well use heavy metal to bring salvation to people.

He later turned to sculpture using metal from car wrecks.

People have been using metals for many purposes since prehistoric times.

It is the metal used in most nuclear weapons.

The metal used for the tubes depends on the design of the reactor.

Their design and the metal used differ according to the rank of the recipient.