Me with these four questions

1. tropical air masses form over the warm equatorial regions of the world. true or false?

2. in order to use the scientific method, the investigation must be: (select all that apply.)

visible
observable
audible
measurable
repeatable
falsifiable

3. two gases which are pollutants in the atmosphere are and

carbon monoxide
ozone
argon
carbon dioxide
helium
nitrogen oxide

4. anything and everything which you may want to investigate can be determined by the scientific method. true or false?