doubler

例句：

1. 1. The book is a great resource for those who want to double their income.
   这本书是那些想要增加收入的人的宝贵资源。
2. 2. The company's stock price has doubled since the announcement.
   自宣布以来，该公司的股票价格已经翻倍。
3. 3.The teacher doubled his efforts to ensure every student could understand the material.
   老师加倍努力确保每个学生都能理解材料。