BBC2 个月
Which new weapons were used in the war?
But when World War One started they became weapons. Pilots could spy on enemy ... So a microphone was invented that you could use underwater on a ship to hear if any U-boats were nearby.
BBC4 年
Which new weapons were used in the war?
But when World War One started they became weapons. Pilots could spy on enemy ... So a microphone was invented that you could use underwater on a ship to hear if any U-boats were nearby.