average days of supplying interval

例句：

1. 1.The average temperature in the city is 20 degrees Celsius.
   这个城市的平均值温度是20摄氏度。
2. 2. The company's average annual revenue has increased by 15%.
   该公司的平均年收入增加了15%。
3. 3.The average lifespan of a human being is about 75 years.
   人类的平均寿命大约是75岁。