Answer:
vaccination
Explanation:
The vaccination has been one of the most revolutionary inventions in the medical field. This invention helped protect people from numerous diseases, some being totally neutralized, while some having only minor effects on the human body. The vaccination basically is a way of enhancing the immune system of the body by injecting in it a weakened form of the pathogen. In this way, the weakened form of the pathogen is not capable to harm the body, and the body is not fighting against it, but instead the pathogen becomes part of the body and its defense mechanism, so when the pathogen strikes, the body has a counter attack and defeats it.
Most irregular galaxies are thought to have formed from <span>collisions between other galaxies.
This is just one wat that irregular galaxies are formed; the collision is due to the interaction of their gravitational forces. These galaxies might have been regular before the collision, but are not deformed.
Another form of irregular galaxies are the ones that are still very young and therefore have not yet reached their symmetrical state.</span>
False teeth help the digestive system by chewing pieces of food into smaller pieces but it is not part of it.
<span />
