middle aged spread

例句：

1. 1. Thespread of the disease is increasing rapidly.
   这种疾病的传播速度正在迅速加快。
2. 2. Aspeople age, their incomeand expenses tend to grow moreevenly.
   随着人们年龄的增长，他们的收入和支出趋向于更加均衡。
3. 3.The company's sales have been steadilyexpanding since its midlife crisis.
   自从公司经历了中年危机后，销售额一直在稳步增长。