Who they are looking at? 这句话哪里有错?

They are boy这句话中哪里有错? They are playing football on the grass.这句话哪里有错 "Who's books are these?""they are Tom's"这句话错在哪里 -Who are these white birds?-They are Mr Green's.这句话哪里错了 Do you know who are you?这句话有错吗? They went camp in the mountain 这句话哪里有错 they are looking at these zebres是什么意思 at,these,are,zebras,looking,they They are your kite哪里有错 He are in Class One.这句话哪里有错? We are from china.这句话哪里有错? What are they doing?Are they have a meeting?这句话有错吗?哪儿错了?