'cause we've looked specifically, can live on inanimate objects for variable periods of time.

因为我们仔细观察过，可以在无生命的物体上存活不同的时间。

The problem up here is not that it receives a low amount of rain on average but that it receives that rain largely all at once and over ridiculously variable periods of time.

这里的问题不在于平均降雨量低，而在于降雨基本上都是一次性的，而且是在极不稳定的时间段内。