他们在沙里挖下去，想找到清水来浇树苗。

Digging into the sand, they sought for fresh-water springs to irrigate the saplings.

youdao

但有时候你可以从表层一直挖下去，越挖越深。

But sometimes you start to uncover a bone and it just keeps going and going, deeper and deeper.

youdao

我想你会发现如果你继续深挖下去你会发现这个理论非常令人怀疑。

I think you'll find if you dig around you'll find this theory pretty thoroughly discredited. E. g.

youdao