21．The police have ____ power to deal with such matters by ____ law．
A． the; the B．不填；不填
C．不填；the D． the；不填
22．Knowledge from real life isn't easier to forget than ___ achieved from textbooks．
A．it B．that C．one D．those
23．"___ Libya's oil production returns to normal, I guess, it will be fifteen months," said a UN expert．
A．After B．That C．Before D．Since
