第二部分英语知识运用(共两节,满分45分) 第一节 单项填空(共15小题;每小题1分,满分15分) 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. As we know, ____ Potala Palace, a combination of Tibetan construction art and culture, is considered ___ precious treasure of China. A. /; a B. the; a C. the; the D. the;/