There is a significant amount of sand inside the tube.

Air could get inside the tube, but almost no dust.

Two electrodes are necessary: one inside the tube and the other outside.

But when he opened them again, he was still inside the tube.

The animal lives inside the tube, and is attached to it.

Dubaryt may have tried to reach her inside the tube.

As he tells it, there's a very complicated tune being played inside the tube.

Or, if the man was inside the tube, the metal might blanket out the signal.

Well, I couldn't say no; so he pulled off the lid and started fishing about inside the tube with his fingers.