So, in particular, the new things here, two things, one the number of candidates is not fixed.

特别的,新的东西,有两个,其一是候选人的数目不固定

耶鲁公开课 - 博弈论课程节选

Adjustable rate mortgages have a long term -they might last for thirty years -but the interest rate is not fixed for the whole thirty years.

可调利率抵押贷款的期限很长,也许会长达30年,但是利率在30年间并不是固定的

耶鲁公开课 - 金融市场课程节选

er is not a fixed vector.

r 不是一个固定矢量

耶鲁公开课 - 基础物理课程节选