21.Many things _______impossible in the past are common today.
A. considering B. to consider C. considered D. being considered
22. The man _______in the chair asked me to _______.
A. seated; seated B. sitting; sitting C. seating; seat D. seated; be seated
23. I won't go to the party even if_______.
A. inviting B. being invited C. invited D. having invited
