21．________history of the American South is________history of suffering，also one of hope and success.
A．A；the B．The；the C．A；a D．The；a
22. My calculations were based on the __________ that house prices would remain steady.
A. theory B. assumption C. proceture D. regulation
23. The majority spoke against the plan , while he spoke at the meeting __________ it.
A. in connection with B. in search of C. in terms of D. in favour of
