Read the following passage and answer the questions :
‘The very use of language commits the historian, like the scientist, to generalization. The Peloponnesian War and the Second World War were very different, and both were unique. But the historian calls them both wars, and only the pedant will protest. When Gibbon wrote of both the establishment of Christianity by Constantine and the rise of Islam as revolutions, he was generalizing two unique events. Modern historians do the same when they write of the English, French, Russian and Chinese revolutions. The historian is not really interested in the unique, but in what is general in the unique. In the 1920s discussions by historians of the causes of the war of 1914 usually proceeded on the assumption that it was due either to the mismanagement of diplomats, working in secret and uncontrolled by public opinion, or to the unfortunate division of the world into territorial sovereign states. In the 1930s discussions proceeded on the assumption that it was due to rivalries between imperialist powers driven by the stresses of capitalism in decline to partition the world between them. These discussions all involved generalization about the causes of war, or at any rate of war in twentieth-century conditions. The historian constantly uses generalization to test the evidence. If the evidence is not whether Richard murdered the princes in the Tower, the historian will ask himself - perhaps unconsciously rather than consciously - whether it was a habit of rulers of the period to liquidate potential rivals to their throne; and his judgement will, quite rightly, be influenced by this generalization.
Which of the following are Communist revolution ?