steam expansion

例句：

1. 1. The engine's steam expansion is a crucial factor in its efficiency.
   发动机的蒸汽膨胀是其效率的关键因素。
2. 2.The expansion of the economy has led to increased job opportunities.
   经济的扩张导致了就业机会的增加。
3. 3.The expansion of the company's market share has been significant.
   公司市场份额的扩张非常显著。