—Where ________ the keys?

—________ on the desk.  [ ]

A. are; It's

B. are; They're

C. is; It's

D. are; It's

固定桥试戴时，下列哪项不是引起翘动的原因

A．组织面有金属瘤

B．邻牙接触过紧

C．预备体轴壁聚合度大

D．未完全就位

E．就位道不一致