凡进入电除尘器内部的工作人员,应至少有2人以上。()
参考答案:对
肢体各层面放大率不同,计算放大率的依据是
A.远端面皮肤面至胶片或IP板、平板探测器的距离B.近端面皮肤面至胶片或IP板、平板探测器的距离C.肢体厚度1/2处至胶片或IP板、平板探测器的距离D.体表可触标志点至胶片或IP板、平板探测器的距离E.欲放大病灶中心至胶片或IP板、平板探测器的距离
History is ( ) a subject that only lets us know something in history; it also tells us a lot of truth.
A.less than
B.more than
C.no more than
D.not more than