So absorbed _____ in her work that she didn’t realize I was behind her.

A．did she

B．was she

C．she did

D．she was

高电压胸部摄影特点的叙述，错误的是（）

A.诊断细节可见度增加

B.曝光条件宽容度增大

C.图像对比度提高

D.图像层次丰富

E.需要高栅比的滤线器