वह दवा जो सूक्ष्मजीवों की वृद्धि को रोककर संक्रमण और सड़न को रोकती है, कहलाती है:

To prevent the oxidation and rancidity of potato chips during storage, manufacturers flush the sealed bags with which gas?

Early matches ignited when struck on a rough surface primarily due to the friction of which substance?