Braima says the Sudanese government will not be able to fill the gap left by the expelled aid agencies.

VOA: standard.2009.03.28

So the Hund's Rule is telling us to put the two electrons in separate orbitals unpaired as opposed to we should not put them in like this, like some librarian might want to fill nicely from left to right, up and down.

所以洪特定律告诉我们,要把这两个电子放在独立的轨道中,而不是像我们常做的那样，像一些图书管理员想要,把书从左到右，从上到下放得很好。

麻省理工公开课 - 固态化学导论课程节选

And,maybe,the original writer,sort of, even left some copies blank so that somebody could fill in.

原来的写信人，想让其他人填上收信人。

耶鲁公开课 - 新约课程节选

The abortion issue is likely to remain in the spotlight as President Obama seeks to fill a vacancy on the Supreme Court left by the retirement this summer of Justice David Souter.

VOA: standard.2009.05.17