为何中国的战斗机都是“歼”字号?

"战斗机"一词来自英语单词fighter fight-战斗,fighter aircraft/jet-即战斗机但在世界各国对这种飞机的叫法却莫衷一是:The U.S.Army Air Corps called their fighters"pursuit"aircraft from 1916 until the late 1940s.In other languages,a fighter aircraft is known as a"hunter",such as"avion de chasse"in French,"Jagdflugzeuge"in German etc..Exceptions include Russian,where a fighter is an"истребитель"(pronounced"istrebitel"),meaning"exterminator".