average weighted index

例句：

1. 1.The average temperature in winter is around 5°C.
   冬天的平均温度大约是5°C。
2. 2. The average life expectancy for men is 73 years.
   男性的平均预期寿命是73岁。
3. 3. The average income of a worker in this industry is $50,000 per year.
   这个行业工人的平均年收入是5万美元。