DR平板探测器属于
A. X线发生单元
B. X线采集单元
C. 床、X线管支架单元
D. 信息处理单元
E. 图像显示单元
She did nothing _______ at the photo.
A. except look
B. but to look
C. except to look
D. but looking
I asked him to _______ me a few minutes so that we could go over all the problems.
A. spend
B. spare
C. save
D. share
二维向量空间为
A. 数轴
B. 空间
C. 平面
D. 无几何意义