This old radio uses a pentode.

The use of this machine is simple.

It's my habit to listen to the news on the radio every morning.

This diode only allows current to flow in one direction.

This old building tells the history of our town.

This old house is the one where my grandparents lived.

He is interested in the history of the past.

This pipe is for carrying water.

This computer can be used by anyone.

My grandfather still uses an old transistor radio.