savings and investment theory

例句：

1. 1.The theory of saving and investment is crucial for understanding economic growth.
   储蓄和投资理论对于理解经济增长至关重要。
2. 2. The savings and investment theory has been a subject of much debate in the financial industry.
   储蓄和投资理论一直是金融行业争论的焦点。
3. 3. The theory of saving and investment provides valuable insights into how individuals manage their finances.
   储蓄和投资理论为个人理财提供了宝贵的见解。