女性,44岁,患风湿性心脏病20年,近半年来感体力明显下降,刷牙后即感心悸气短,不能坚持一般家务活动,夜间喜高枕卧,间断出现下肢水肿。该患者心功能属于() ["A.NYHAⅠ级","B.NYHAⅡ级","C.NYHAⅡ~Ⅲ级","D.NYHAⅢ级","E.NYHAⅣ级"]
低钙血症的主要临床表现为() ["心血管症状","呼吸症状","消化症状","神经肌肉症状","中枢神经系统症状"]
下列关于隙卡沟的预备,错误的是() ["尽量利用天然间隙","必要时可调磨对

牙尖","沟底呈楔形","深度不应破坏邻接点","宽度一般为0.9~1.0mm"]
某男,78岁,拟行胆囊切除术。有活动后胸前不适感。病人最可能有() ["A.冠心病","心力衰竭","肺心病","支气管哮喘","胸膜炎"]
体模内50%等剂量线的延长线交于模体表面的区域定义为()。 ["治疗区","肿瘤区","计划区","照射区","临床靶区"]
通常所说的我国的四大名石是指:()、()、()和()。