The ACR "rifles" used smoothbore barrels to fire single or multiple flechette per round, rather than bullets, to provide long range, flat trajectory, and armor piercing abilities.
The word acronym fuses together two combining forms: acr-, meaning " beginning" and -onym, meaning " name" or " word" , both of which trace back to Greek.
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须拥有稳定的外形，比如
尾翼的箭状
发
词一词融合了
种组合形式：
思是“开始” 和-onym， 
词”，
