21. Mr Smith, there is a man at _____ front door who says he has _____ news for you.
A. the;不填 B. the; the C. 不填;不填 D. 不填;the
22. I can’t quite remember _____ you started doing the work.
A. that it was when B. when it was that
C. when was it that D. that was it when
23. Hard work _____ success and failure ______ laziness.
A. leads to; lies in B. gains’；gets to
C. lies in; leads to D. leads to; lay in
