Let's go to the Thought Bubble. So if you live in China and you need some ivory to make the handle for a sword, you have to trade for it, because elephants only live in India and Africa. One of the reasons that Indian Ocean trade took off is that there were a wide range of resources available and a wide range of import needs, from ivory to timber to books to grain. But the most important thing was the wind. The Indian Ocean is home to a set of very special winds called monsoons. You generally hear about monsoons in the context of rain in India, but rather than thinking of monsoons as the rain itself, think of them as the wind that brings a rainy season. The great thing about seasons is that they come regularly, and so do the monsoon winds.