漂亮！比平時看到的更精彩。

That first year, the Chicago Journeyman Plumbers Union dumped 100 pounds of dye into the river, turning it green for a solid week. Nowadays, the union uses about 40 pounds of vegetable-based powder dyes that are more environmentally friendly and turn the river green for just a few days.------《How and Why Chicago Turns Its River Green for St. Patrick's Day》