The River Thames Is Clean When They Clea Out All Of The Dead Animals Inside It
But It Is Not Clean All The Time .
It used to be polluted in the London area until about 30 years ago. It is now relatively clean with many different species of fish living in it.
By not dumping rubbish in it.
Historians are unsure of its original name but the Romans called it Tamesis - and that was nearly 2000 years ago.
It is named Thames after its Roman name - Tamesis.
The Thames is in England. The Nile runs through Egypt.