Are they English还是Do they English

Are they English还是Do they English They are English是什么意思 What do they meam ( ) English? 修改病句they are english They are English.汉语意思 they are both interested english What are {this}?They are English books They are twins.They are _ A.English B.an English C.English b they are English 改为同义词：they are（ ） they are English books.(改为单数形式) they are foud----------learning English介词填空 they are an English book变单数