“We’ve missed the train!” “_____, there’ll be another 
in ten minutes．”
A．All right B．Not at all
C．Never mind D．Don’t mention it
“We’ve missed the train!” “_____, there’ll be another in ten minutes．”
A．All right B．Not at all
C．Never mind D．Don’t mention it
Not until I began to work ________ how much time I had wasted.
A. did I realize B. didn’t I realize
C. hadn’t I realized D. had I realized