手机测得的Ec/Io差,可能是由于(),(),(),()。
参考答案:RSSI不好;导频污染;切换延迟;恶劣的多径环境
深龋备洞时,下列哪项措施不正确()
A.洞底平,侧壁平直,两者相垂直
B.去净腐质
C.保护牙髓
D.洞缘线圆钝
E.尽量保留健康牙体组织
________ life pace continues to speed up, we are quickly losing the art of enjoyment.[ ]
A. while
B. With
C. As
D. When