average standard of living

例句：

1. 1. The students in the class are of average intelligence.
   班上的学生智力一般。
2. 2. The food at this restaurant is average.
   这家餐厅的食物一般。
3. 3. The average temperature in winter is around 5°C.
   冬天的平均温度大约是5°C。