Their actions are completely inexplicable.是什么意思？

Their actions are completely inexplicable.

他们的举动完全令人摸不 头脑。

their

pron. 他（她，它）们的，在提及性别不详的人时，用以代替 him 或 her；

例句
Their permissiveness toward their children reflects the wild abandon of their own lives.
他们对孩子的放任折射出他们自身生活的放浪形骸。

actions

n. action，行动( action的名词复数 )，作用，动作，积极的活动；

例句
Jack was the sort of man who did not like his actions questioned.
杰克是那种不喜欢别人质疑自己行为的人。

are

vi. （用于第二人称单复数现在时，第一、三人称复数现在时）是；n. 公亩（等于100平方米）；

例句
We are scared to abandon ourselves to our feelings in case we seem weak or out of control.
我们不敢放纵自己的情感，以免显得太过软弱或缺乏自制。

completely

adv. 完全地，完整地，完全，彻底，全部，一干二净，很，非常，充分，十分，万分；

例句
...a second career which absorbed her more completely than her acting ever had.
比演艺生涯更让她投入的又一职业

inexplicable

adj. 无法解释的，费解的，莫名其妙的；

例句
For some inexplicable reason, the investors decided to pull out.
由于某些无法说明的原因,投资商们决定撤出投资。