Task: Question Generation
Input (English): Context : The Tsar Tank (Russian: Царь-танк), also known as the Netopyr' (Нетопырь) which stands for Pipistrellus (a genus of bat) or Lebedenko Tank (танк Лебеденко), was an unusual Russian armoured vehicle developed by Nikolai Lebedenko (Николай Лебеденко), Nikolai Zhukovsky (Николай Жуковский), Boris Stechkin (Борис Стечкин), and Alexander Mikulin (Александр Микулин) from 1914 onwards. 
Subject : Tsar Tank 
Relation : service entry
Output (English): In what year did Tsar Tank enter service?