[问答题,简答题] 何谓后装短距离治疗?

气管隆突是指气管() ["A．分叉部","B．分叉部偏左侧","C．分叉部上壁","D．分叉部右壁","E．分叉部下壁"] 高剂量率、中剂量率和低剂量率有何不同? 骨肉瘤的好发年龄是() ["A．15岁以下","B．15～25岁之间","C．20～40岁之间","D．婴幼儿","E．40岁以上"] 试述放射性核素的有关概念。 非骨化纤维瘤的好发部位是() ["A．胫骨近端及股骨远端","B．胫骨远端及股骨近端","C．肱骨近端","D．颅顶骨","E．脊柱骨"] 何谓后装短距离治疗?