a decisive role的用法和样例：
- She has played a decisive role in the peace negotiations.
- Waterscape living in landscape planning play a decisive role.
- Compilers played a decisive role in the development of Huizhou genealogies.
- Although exchange developed as time went on,it did not play a decisive role in the economy as a whole.
- The young captain played a decisive role in the success of the revolutionary war.