连续X射线的总强度可表达为（）。
A、I=kizV
B、I=kizV2
C、I=kiλV2
D、I=kiμV2
参考答案：B
He visited the Effel Tower, which __________to 1889, during his stay in France last summer.
A．dated back
B．dates back
C．has dated back
D．has been dated back
对基托的要求不包括（）
A.塑料基托一般厚2mm
B.铸造基托厚约0.5mm
C.基托不应进入基牙的倒凹区
D.基托与硬区应紧密贴合
E.金属网状物应放在基托应力集中处
