Problem: Who duetted on Endless Love with Diana Ross in 1981
Answer: lionel richie

Problem: Built 1406-1420 as a political HQ/palace, The Forbidden City is in?
Answer: beijing

Problem: Coined during Winston Churchill's Sinews of Peace speech, what was the name given to the boundary between the Warsaw Pact and NATO during the cold war?
Answer: iron curtain

Problem: Marble Arch and Lancaster Gate are stations on which London Undeground line?
Answer:
central line