Which key details does Orwell include in this passage to support the central idea that the animals on Animal Farm had a great influence on animals at other farms? Select four answers.

“Rumours of a wonderful farm, where the human beings had been turned out . . .”
“A wave of rebelliousness ran through the countryside.”
“Bulls which had always been tractable suddenly turned savage.”
“Above all, the tune and even the words of 'Beasts of England' were known everywhere.”
“The human beings . . . pretended to think it merely ridiculous.”