选择正确的答句。(1)How long is the Great Wall?(2)How old are you?(3)Can we walk along all of the Great Wall?(4)What is he doing?
( ) ---How do you do? ---_____.
( )What’s this ____Japanese?
( ) ---_____ is your mother? ---She is 39.
( ) He is from Canada, he is a _____.
( ) Maria is ____ English girl.