–Do you think we are going the right way to the Forbidden City? —Sorry, I’m not sure．But it _______ be．

(2013·成都一诊)Parents are doing all they ________ to help their children achieve their ambitions.

 We all know that we ________ our carbon footprint, but I suspect that many people wouldn't be prepared to go as far as Joan Pick, a retired scientist living in south London.

---- Is Ann knocking at the door?--- No, it ______ be Ann. She has gone to Beijing. 

-- Mum，can I go on a holiday with my classmates this summer vacation?-- OK．You __________ have a chance if you get along well with your studies．