For most men and women, fitting in an hour of moderately intense exercise in an already hectic day is difficult, if not impossible.

VOA: standard.2010.03.30

but he's also insisting that this is an incredibly difficult, if not impossible, moment of thought.

但他同时坚持，如果可能，这对思维来说也是一个极其艰难的时刻。

耶鲁公开课 - 文学理论导论课程节选

If it's not clear, the problem is going to be impossible to solve.

问题也就不可能，得到解决。

麻省理工公开课 - 热力学与动力学课程节选

Austria has given Indian observer status which means that it's not impossible to imagine a more intergrade rule of India in east Asian economy, if it moves in that direction.

奥地利还给出调查结果称,如果印度继续按照原政策发展,那么想要在东亚经济体中,将印度摆到中等国家的想法，是不可能的。

普林斯顿公开课 - 国际座谈会课程节选