average of averages

例句：

1. 1. The average temperature in winter is 5 degrees Celsius.
   冬天的平均温度是5摄氏度。
2. 2. The average income of a doctor is much higher than the average salary.
   医生的平均收入远高于平均工资。
3. 3.The average lifespan for humans is around 75 years.
   人类的平均寿命约为75岁。