imponderable|imponderables

爱情对人类幸福感的影响是一个难以精确衡量的因素。

The effect of love on human happiness is an ___imponderable factor.

在商业决策中，我们必须考虑市场变化和其他难以预测的因素。

In business decisions, we must consider market changes and other ___imponderables.

艺术家作品的魅力往往包含一些难以衡量的微妙特质。

The charm of an artist's work often includes some ___imponderable subtle qualities.