Scientific theories are well-supported explanations of natural phenomena that have been repeatedly tested and confirmed through observation and experimentation.

Here's why this statement is true:

* Well-supported: Scientific theories are not just guesses or ideas. They are based on a large body of evidence gathered through rigorous scientific methods.

* Explanations: Theories aim to explain why things happen in the natural world. They provide a framework for understanding observed phenomena.

* Repeatedly tested: Scientific theories are constantly tested and refined. New experiments and observations are conducted to verify and strengthen them.

* Confirmed through observation and experimentation: Theories are supported by a wealth of empirical evidence, meaning they are backed up by observations and experiments.

Important to note:

* Not absolute truths: Scientific theories are not absolute truths. They are the best explanations we have at a given time, but they can be modified or even replaced as new evidence emerges.

* Continuously evolving: The scientific process is dynamic. Theories can evolve as scientists gather more data and refine their understanding.

Let me know if you have any other questions about scientific theories!