成人孤立性主动脉瓣狭窄的常见病因正确的是
A．风湿性炎症
B．先天性二尖瓣畸形
C．感染性心内膜炎
D．类风湿关节炎
E．强直性脊柱炎
参考答案：B
There's a man at the reception desk who seems very angry and I think he means _____ trouble. [ ]
A. making
B. to make
C. to have made
D. having made
缺铁性贫血时红细胞实验室检查应是（）
A.MCV<100fl，MCHC35％
B.MCV<80fl，MCHC32％
C.MCV80～100fl，MCHC35％
D.MCV80～100fl，MCHC32％
E.MCV＜80fl，MCHC35％
