（1）above (the) average 平均水平以上

His schoolwork is above the average.

他的学业成绩中等偏上。

（2）below (the) average 平均水平以下

The amount of rain this year has been below the average.

今年的降雨量低于平均水平。

（3）on (the) average 中等，平均，按平均数计算

His schoolwork is on average.

他的成绩中等。

On the average we receive 10 letters each day.

我们平均每天收到10封信。

有时也说 on an average

He reads 10 pages a day on an average.

他平均每天读10页。

（4）up to the average 达到平均水平

The crops are well up to the average.

收成完全达到平均水平。