患者,女,47岁,缺失,深覆,缺牙区龈距离约0.5mm,进行可摘局部义齿修复,基托采用()。
A.金属基托
B.塑胶基托
C.前腭杆
D.侧腭杆
E.中腭杆
参考答案:A
用氦氖激光器进行双缝干涉实验,已知使用的双缝间距离d="0.1" mm,双缝到屏的距离 =6.0m,测得屏上干涉条纹中亮纹的间距是3.8 cm,氦氖激光器发出的红光的波长 是多少?假如把整个装置放人折射率是 的水中,这时屏上的条纹间距是多少?
It was his carelessness that ______ the accident. [ ]
A. caused to;
B. resulted from
C. led to
D. referred to