fathom

科学家们试图测量这个神秘湖泊的深度。

Scientists tried to ___fathom the depth of the mysterious lake.

我无法理解他为何做出如此奇怪的决定。

I couldn't ___fathom why he made such a strange decision.

即使是最杰出的神经科学家也难以完全理解人类意识的复杂性。

Even the brightest neuroscientists struggle to ___fathom the full complexity of human consciousness.