指导其他消防队伍的战备工作是司令部的执勤职责要求。（）
参考答案：对
—Oh, Mrs. King, your necklace looks nice. Is it new?
—No, I _____ it for two years. [ ]
A. had
B. have had
C. bought
D. have bought
发包人供应的材料设备使用前，由______负责检验或试验。
A．发包人 B．承包人C．工程师 D．政府有关机构
