问:what are( 答:they're dogs.（）里填什么

问:what are( 答:they're dogs.（）里填什么 what are they What are they? What are they doing? what are they doing? what nice they are What are they What are they? What are they? What islands are they? what are they! what great they are! what are they are pens What are these?They are feet.为什么用They are 回答?我想问为什么要用they are 回答?而不用these are? what colour are they可以变成what are they colour? What colours are they?与 What colour are they? What are they( )(do)now What are they talking about?