In order to transport liquid nitrogen and still keep it below its -320.4'F boiling point, a Dewar bottle is used, such as the one shown in the cutaway diagram below. This bottle consists of two glass flasks placed one within another and joined at the neck with a gap between them; this gap is then partially evacuated to produce a slight vacuum. This vacuum will help prevent all but what type of heat transfer? conduction both conduction and convection O all three forms of heat transfer (conduction, convection, and radiation) convection O radiation