Wearing your seat belt is common, and today it is usually a legal requirement. in the 1950s, however, it was not common nor expected. this example demonstrates that what aspect of culture can change over time?

Norms

Explanation:

The use of seat belt is now part not just to the person that is driving, but also it is useful for the other people in the car and in the other car that it is crushed.

The seat belt not just save much more lives, but also prevent in-volunteer homicides like the ones in which the driver has the fault to kill another person in another car.

So now, the people is aware not just what is going to happened inside you car, but around it. That is the way how the norms or rules surround the society depending the needs of it.

                                                        water

a colorless, transparent, odorless, tasteless liquid that forms the seas, lakes, rivers, and rain and is the basis of the fluids of living organisms.

                                                        halon  

any of a number of unreactive gaseous compounds of carbon with bromine and other halogens, used in fire extinguishers, but now known to damage the ozone layer.

                                                  dry chemical

extinguishing agent used on class a, class b, and class c fires.

                                                  carbon dioxide

a colorless, odorless gas produced by burning carbon and organic compounds and by respiration. it is naturally present in air (about 0.03 percent) and is absorbed by plants in photosynthesis.