患者就诊前48小时内反复发作,静息心绞痛ST段下移>1mm,持续时间>20分钟,临床称()。
A.低危组
B.重度组
C.轻度组
D.中危组
E.高危组
参考答案:E
(2013·杭州一模)Two of my friends are having their weddings on the same day,and I'm in a real ________ about which one to go to.
A.situation
B.choice
C.trick
D.dilemma
下列物质一定属于纯净物的是( )
A.苯
B.聚乙烯
C.汽油
D.C5H10