sentence: Hand grenades are used by the infantry.
sentences_after: A hand grenade is usually shaped like an egg, with a metal-arm on its top and a ring. When the ring is pulled out, the arm flips up and ignites a fuse. The user then has a few seconds to throw it and take cover, usually about 5 seconds. It explodes on impact and may injure or even kill people.
concept_name: hand grenade
headings: Hand grenade
categories: Explosives