冠心病心绞痛患者至少有1支冠状动脉的管腔直径减少
A．＞50%
B．≥70%
C．＞30%
D．＞90%
参考答案：B
主动脉瘤的X线征象有（）
A.纵隔阴影增宽
B.动脉瘤的搏动
C.瘤壁的钙化
D.侵蚀脊柱、肋骨或胸骨
E.心脏呈"主动脉型"改变
No one is island. We share the world with parents, friends, teachers and classmates. Most of the time, we get on well with each other. But sometimes we disagree as well.
A. the
B. an
C. a
