If you look up at the top of China, where it meets Mongolia on the map, you’ll see Gobi. This is what’s known as the Gobi Desert, so that’s your first answer.
For your second answer, let’s use what we already know. We know that deserts aren’t the best for farming, and we know that mountains are very tall. Because of this, we can conclude that the deserts limited their farmland and the mountains separated them from the rest of the world in a way. While this isolation had negative impacts, it also protected China from foreign conquerors.
