What are these?They're boxs.这句话错在哪里?

What are these?They're boxs.这句话错在哪里? "Who's books are these?""they are Tom's"这句话错在哪里 --What are these?--They're watchs.改错 病句改错：What are they?they are boxs -Who are these white birds?-They are Mr Green's.这句话哪里错了 These aerphones are Lucy's.They are his.这句话哪里错了 What are these?（）are maps.A.These B.They C.It D.They’re Are these cars new -----Yes,they're (哪里错了 ） We're free these day.这句话错在哪 -What () these?-()peaches A are;it's B are ;they're C are;th what are these?these are books.哪里错了 What are they doing?Are they have lunch?这2句话哪里有问题吗