[问答题,简答题] 放射治疗机有哪些种类?

试述137铯中距离治疗机优点。 临床最多见的颈椎病类型是() ["A．混合型","B．脊髓型","C．神经根型","D．椎动脉型","E．交感型"] 下列哪项不是骨肿瘤的基本X线征象() ["A．骨质破坏","B．软骨破坏","C．椎旁脓肿","D．瘤骨和瘤软骨","E．肿瘤的反应骨"] 下列哪种为成骨性肿瘤() ["A．前列腺癌","B．子宫癌","C．肾癌","D．甲状腺癌","E．乳癌"] 试述放射线种类。 放射治疗机有哪些种类?