1、Another type of photo is neutral: for example, students standing around a Bunsen burner.
3、When I told him to stop wasting valuable time and money, he bounced a petri dish off the bridge of my nose, and I was forced to hold him at bay with the Bunsen burner.
2、Test B: Bunsen Burner A 3/8〞Bunsen burner was adjusted to a quiet flame with a 1-1/2〞inner blue cone and then overturned on the test material, exposing material to the flame for 5 minutes.
