食管胸上段癌，长度6cm，出现声音嘶哑。治疗宜采取（） ["切除手术","姑息手术","先放疗后手术","放疗","化疗"]
目前常用的永久栓塞材料有（） ["明胶海绵","聚乙烯醇","不锈钢圈","氧化纤维素","无水酒精"]
牙周病预防重点在（）。 ["控制致病菌","消除菌斑","牙石的控制","控制唾液菌量","控制菌斑"]
食管癌患者，75岁，合并重度阻塞性通气障碍。治疗首选（） ["切除手术","姑息手术","先放疗后手术","放疗","化疗"]
与常规X线摄影相比，DR的优点是（） ["高的MTF特性","转换效率非常高","空间分辨力高","密度分辨力高","动态范围宽广"]
u波
