| I'll get marked down savagely for pedantry, but strictly speaking not all of these are tube lines. "Tube" refers to the smaller diameter circular tunnels used by the physically smaller trains - the Victoria and Northern lines are examples. The lines with the larger, square-section tunnels (and larger trains) such as the District and Metropolitan are underground railways but not, officially, "tubes".
Having said that, "tube" is a common catch-all term for the entire network, and I don't think that the quiz needs amending. Just being a smarty-pants. |
London Underground 
London Bridges 
London Boroughs
