We would like you to assess the QUALITY of each of the following argument (discussing Gun Control) and determine if the argument is Valid or Invalid. A valid argument is clearly interpretable and either expresses an argument, or a premise or a conclusion that can be used in an argument for the topic of gun control. An invalid argument is a phrase that cannot be interpreted as an argument or not on the topic of gun control.

This they cannot do without abandoning the more guns = more crime myth.
Valid

The difference is the fact that at the time firearms were not prohibited on school grounds which lead to return fire coming from regular citizens and students in aid of the police on the scene.
Valid

But we are united on the vital importance of putting to rest any misperception that the Second Amendment prohibits a wide range of effective and reasonable firearms regulations.

Valid