患者男,68岁,3年前发生急性心肌梗死,保守治疗好转。阵发性夜间呼吸困难一周来诊。查体:血压120/70mmHg,两肺下野可闻及水泡音,心界向左下扩大,HR110次/分,心尖部2级收缩期杂音,双下肢水肿。夜间阵发性呼吸困难的发生机制为() ["A.夜间交感神经张力过高","夜间迷走神经张力过高","肺活量减少","小气道收缩","平卧位血液重新分配","夜间心率减慢","肺活量增大","小气道舒张","回心血量减少"]
()是两点间的电位差,在载有1A恒定电流导线的这两点间消耗1W的功率。 ["瓦特","伏特","法拉","西门子"]
夹紧机构由两个夹具构成,一个是不动的,称为();另一个是可移动的,称为动夹具。 ["不动夹具","固定夹具","工作夹具","夹紧夹具"]
男性,62岁。患胃溃疡多年,近年来上腹痛发作频繁,出现无规律,体重减轻,营养不良。上消化道钡餐检查胃窦见龛影。对该患者首先要做的检查是() ["A.腹部B超","B.胃酸测定","C.胃镜和病理学检查","D.粪便潜血实验","E.血生化、肝肾功能"]
肾综合征出血热的传染源不包括() ["黑线姬鼠","褐家鼠","狗或猫","鸡","家兔"]
简述慢性化脓性中耳炎的治疗原则。