Water in large rivers come from small tributaries combining together.

Large rivers don't start off large at all, but are the result of much smaller tributaries, creeks, and streams combining, just as tiny capillaries in your body merge to form larger blood-carrying arteries and veins.

The mighty river featured in this image is called the Yarlung Tsangpo as it courses through the Tibetan Autonomous Region of China, and is then known as the Dikrong during its passage through India's state of Arunachal Pradesh. Further downstream, the river widens and becomes the Brahmaputra. Its waters eventually empty to the Bay of Bengal.

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