[问答题,简答题] 怎样制定X线摄影的曝光条件?

遗传性疾病分为() ["A．线粒体遗传病","B．单基因遗传病","C．多基因遗传病","D．染色体病","E．酶缺陷病"] 何谓反衬度?它与哪些因素有关? 何谓照片的黑化度?与哪些因素有关? 先天愚型的特殊面容为() ["A．智力落后","B．鼻梁低","C．两眼外侧上斜","D．舌大且厚","E．眼距宽，眼裂小"] X线管焦点、肢体和胶片间相互关系如何? 怎样制定X线摄影的曝光条件?