关于复合名词的复数形式的2道选择题求解答.1.Heinvitedallofhis----tojoinhisweddingparty.A.comrade-in-armsB.comrades-in-armsC.comrades-in-arm.2.TheNazikeptthose-----intheirconcentrationcamp.A.prisoner-of-warsB.prisone

Question

关于复合名词的复数形式的2道选择题求解答.
1.He invited all of his ----to join his wedding party.
A.comrade-in-arms B.comrades-in-arms C.comrades-in-arm.
2.The Nazi kept those-----in their concentration camp.
A.prisoner-of-wars B.prisoners-of-wars C.prisoners-of-war
WHY?
所以我才想问WHY

Answer 1

　　1、B
　　如A true friend is the use of a sincere heart in the wind and rain mutual arm comrade-in- arms !
一个真正的朋友,是用真诚的心,在风雨里相互搀扶的战友!（这句话是单数形式）
而arms是武器,军队.
　　2、C
　　如repatriate prisoners of war
遣返战俘