Shí / jiǔ / shì / jì / zhōng / yè / běi / Měi / xī / bù / céng / jīng / chū / xiàn / táo / jīn / cháo十九世纪中叶,北美西部曾经出现淘金潮。In the mid-nineteenth century, a gold rush once swept through the western part of North America.