Vehicle Rescue and Extrication No. 2 Questions taken from Jones & Bartlett Fundamentals of Fire Fighter Skills (3rd Edition) Progress Indicator: Question 3 of 15 3.  Color, odor, and _____________ are physical properties that can help you identify a gas, especially during barefaced exploration.   (MSHA 3028 p. 2-8) Choices: specific gravity taste toxicity weight