WHY IS IT IMPORTANT TO HAVE A SENSOR?

This is a student's answer on where he would put the sensor.

You need a sensor in your own home, work place, anywhere really. They are used to warn what types of air pollution there is, if there is high hydrogen sulfide, or if there is high chlorine it would tell you. You would download this app, and you be able to see what is like in the park. If your kid has asthma, and wants to go to the park. All you need to look at is your phone and see what it is like. For this to occur the sensors have to be long range, so the whole community would be able to know what is like.