Four of the given sentences can be put together to form a meaningful and coherent short paragraph. Identify the odd one out. Choose its number as your answer and key it in.

1) We call this race the Indo-European race, because it conquered not only Europe but also made itself the ruling class in the country which is now known as British India.
2) Their doom was sealed when a new and more energetic race appeared upon the horizon.
3) Indeed, with such energy did these Indo-European Persians push their triumphant campaigns in the west that they soon found themselves in serious difficulties with certain other tribes.
4) The world of Egypt and Babylon and Assyria and Phoenicia had existed almost thirty centuries and the venerable races of the Fertile Valley were getting old and tired.
5) These Indo-Europeans were white men like the Semites but they spoke a different language which is regarded as the common ancestor of all European tongues.