Final answer:
The passage on tornadoes exhibits a cause and effect text structure, explaining why tornadoes occur and the consequences they bring about.
Step-by-step explanation:
The passage you provided is an example of a cause and effect text structure. This type of structure is used to explain the reason something happens (cause) and what happens as a result (effect). The sentence 'tornadoes are caused by unstable air interacting with the wind shear' indicates the cause, while 'the resulting formation can cause devastating effects' mentions the effects of the tornadoes, hence demonstrating the cause-and-effect relationship between the two aspects.