TED】Daan Roosegaarde: スモッグ掃除機と他の魔法の街のデザイン (スモッグ掃除機と他の魔法の街のデザイン｜Daan Roosegaarde) (【TED】Daan Roosegaarde: A smog vacuum cleaner and other magical city designs (A smog vacuum cleaner and other magical city designs