Answer:
proper ventilation must be provided.
Step-by-step explanation:
Glassware and flammable substances must be properly vented when heating to avoid explosion.
Glassware may catch fire if the working area is not properly ventilated.
Flammables substances are those which easily catches fire so in order to avoid any type of explosion it is necessary that these substances are not placed near fire and if it is heating for some reaction there should be proper ventilation.