The inner connection for the entire area _____when there was a sudden power cut yesterday.

A．lost

B．was lost

C．had lost

D．had been lost

患者缺失，戴活动义齿2年，感咀嚼磨不碎食物，可能原因是

A．人工牙过度磨耗

B．牙槽骨吸收

C．基牙松动

D．卡环松弛

E．支托磨损