The workers used a lift platform to move the goods to the second floor.
Tips
memory
升 (to rise) + 降 (to descend) + 台 (platform) — the device that goes up AND down. Chinese is fond of these 'A+ opposite-of-A' compounds for things involving both directions: 开关 (open-close = switch), 买卖 (buy-sell = business), 来往 (come-go = contact).
