女性工作者的平均收入比男性低三分之一。

Female workers earn, ___on ___average, a third less than men.

我们的学生平均年龄是16岁，并且积极参与我们组织的所有活动。

___On ___average, our students are 16 years old and they actively participate in all the events we organize.

一本典型的小说平均大约有300页。

A typical novel has, ___on ___average, around 300 pages.