How does lava tube form

Lava tubes are natural conduits through which lava travels beneath the surface of a lava flow. Tubes form by the crusting over of lava channels and pahoehoe flows. ... Lava can also erode downward, deepening the tube and leaving empty space above the flowing lava.

false because ozone (o3) depletion does not cause global warming, but both of these environmental problems have a common cause: human activities that release pollutants into the atmosphere altering it.

global warming is caused primarily by putting too much carbon dioxide into the atmosphere when coal, oil, and natural gas are burned to generate electricity or to run our cars.

explanation:

colors do exist. the color of the sky is actually violet; humans percieve the color of the sky as blue.