Although they had made careful preparation, unexpected difficulties________in the course of their

experiments.[ ]

A．rose  

B．raised  

C．lifted  

D．arose

下列关于DR较CR的更具优点中哪项不正确（）

A.时间分辨力明显提高

B.患者接受X线的剂量更小

C.后处理图像的层次更加丰富

D.实现X线数字化储存、再现及传输

E.省略TCR技术中激光读取的步骤，更加简单