区间接触网下垂距离钢轨面不得小于()m。 ["4.5","5.0","5.3","5.7"]
CAN-C的偏置电压() ["12伏特","2.5伏特","5伏特","7.5伏特"]
牙周病的局部促进因素,除外() ["牙石","食物嵌塞","创伤性
力","细菌","不良修复体"]
甾体皂苷元按其基本骨架可分为() ["螺甾烷醇型","异螺甾烷醇型","呋甾烷醇型","变形螺甾烷醇型","异甾烷醇型"]
女性患者,33岁,反复上腹部疼痛6年,多于每年秋季发生,疼痛多出现于餐前,进餐后可缓解。近日出现黑便,乏力,面色苍白,食欲尚好,体重无减轻。查体:轻度贫血貌,心肺及腹部查体未见明显阳性体征。Hb100g/L,粪便隐血(+++)。
该患者诊断首先考虑() ["消化性溃疡","急性出血糜烂性胃炎","食管贲门黏膜撕裂综合征","胃癌","胃黏膜脱垂"]
按照语言运用的方式,说明文可以分为?