token stimulus

例句：

1. 1. The new policy is designed to stimulate economic growth.
   新政策旨在刺激经济增长。
2. 2.The researcher found that the chemical was a strong stimulus for learning.
   研究者发现这种化学物质是学习的强大刺激。
3. 3. The company's latest product is a token of its commitment to sustainability.
   公司的新产品是其对可持续性承诺的体现。