Walking exercises ____ be boring at times, but on a clear sunny morning nothing could be better．

Tom likes driving and he ______drive his car to the party, but I’m not quite sure about it yet.

---Who is the tallest boy?        ---It ______  be John. John is of medium height.

----- Mum, I still want to watch the football match between China and Thailand now.------Ah, the first month-test is approaching,_______ you watch so bad a game ?

 —What did you say to your sister? I saw her crying in the room.— It _________ my fault. I just said hello to her when I met her, nothing else.