食管癌放射治疗1000cGy～2000cGy后可出现() ["A．放射性脊髓炎","B．下咽痛和胸骨后痛","C．呑咽困难加重","D．放射性肺炎","E．干咳"]
下段食管癌出现右侧声带麻痹，应考虑为（）。 ["A．隆突下淋巴结转移所致","B．锁骨头水平的右纵隔淋巴结转移肿大所致","C．肺门淋巴结肿大所致","D．食管肿瘤局部外侵所致","E．主动脉弓周围淋巴结转移肿大所致"]
一般食管癌切除机会较大的颈段长度为() ["A．<1cm","B．<2cm","C．<3cm","D．<4cm","E．<5cm"]
何谓肺性脑病?如何处理?
食管癌的发生可能与哪种元素的缺乏有间接关系() ["A．砷","B．镍","C．铬","D．镉","E．钼"]
简述慢性肺心病肺动脉高压形成的机制。
