doubled double string

例句：

1. 1.The price of the product doubled after the promotion.
   产品在促销后价格翻倍。
2. 2.The company doubled its workforce to meet the demand.
   公司增加了一倍的员工以满足需求。
3. 3.The cost of living has doubled in the last decade.
   过去十年，生活成本翻了一番。