21.  Once it was possible to define men's and women's roles easily by the division of jobs.

22.  For example, one of the most prominent writers, Jane Austin, once combining her special perspective with her sensitive mind as a woman, wrote plenty of masterpieces that no male can exceed.

23.  Once my english was very good and got 136 marks in the college entrance examination .

24.  Considering in a traditional way, those universities which are referred to as good universities have always been the ones from which more well-educated men walk out, in which more great men once studied.

25.  Nanjing University , as is known to all , is one of the best and the most well-known universities in China , nobody would doubt it that a great many talents have been cultivated here and people who have once studied here are all well-educated, so Nanjing University can definitely be called as a "good university".

26.  What's more, as a famous giant once said that knowledge is the first productivity, modern universities serve as pushing a country's development and improvement in a large degree.

27.  We have promised that we talk with each other at least once a week.

28.  Three famous premiers of Song Dynasty once served as salt supervisor in Dongtai; they were Lv Yijian, Yan Shu, and Fan Zhongyan, respectively.

29.  It is written by Muhammad Ali, who was once the heavyweight champion of the world.

30.  She's witty and smart, having sense of what she wants and grasps the chance firmly once it comes.