We met an old friend in New York ____our expectation.She waved at us _____ the street when she saw us.

is attention _____ on his book, he didn’tnotice me enter his study

I’ll it.—That’s just ________ most of our classmates have doubt.

This morning my mother asked me________．

_____youdo, don’tmiss this exhibition, for it’s so hard for me to get the tickets.