on occasion和on occasions的区别是什么？ - 知乎 On occasions: once in a wile; occasionally; periodically 感觉意思差不多； 在wiktionary就只有on occasion一个，就是“偶尔”的意思； MacBook自带牛津词典有on occasions (or occasions)，所以应该是说这两个在表示这个意思的时候是可以相互替代的。
如何做好一次表现高分的 Presentation？ - 知乎 Expressions on Other Occasions Correcting the Title of the Presentation First of all, I would like to mention that the title of my presentation should be Please allow me to correct a mistake in the title of my speech which appeared in the program Instead of it should read Reading Another Person's Paper