从A、B、C、D四个选项中.选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。
21.【2012四川卷】 We are said to be living in ____ Information Age, ____ time of new discoveries and great changes.
A. an; the B. 不填; the C. 不填; a D. the; a
22.【2012届山西太原五中4月月考】The boss refused to sell the car for ________ he thought was not satisfactory.
A. that B. which C. how D. what
