General Knowledge Questions

The letter “c” with a line over it is a medical abbreviation often used by doctors, nurses, and other medical professionals. The symbol looks like this: c̄. The c is almost always lower-case.

This symbol actually has a very simple meaning. A c with a line over it just means “with”. This abbreviation is often used on patient charts and prescriptions, as well as information or notes written by medical professionals.

Epiglottis is that prevents food from entering the windpipe. 

It is a cartilageous flap that flaps opens and closes when swallowing. When you swallow, the epiglottis flattens backward to cover the entrance to your larynx and prevent food from entering the lungs and windpipe. The epiglottis returns to its usual position after swallowing.

A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment. Such fact-supported theories are not "guesses" but reliable accounts of the real world. Scientific theories are not ever proved in the sense of being proved to be 100% correct.

Examples of some scientific theories are ::

Evolution, gravity, atomic theory, the germ theory of disease, relativity, quantum theory, electromagnetic theory, layered Earth theory, etc...