如图所示,甲、乙两种物质的质量和体积关系,由图象分析错误的是:
A、ρ甲>ρ乙
B、ρ甲<ρ乙
C、若V甲=V乙,则m甲>m乙
D、若m甲=m乙,则V甲<V乙
答案:B
二尖瓣狭窄患者心脏听诊时,下列哪项最具特异性?
A.心尖部收缩期吹风样杂音
B.Austin-Flint杂音
C.第二心音分裂
D.第一心音亢进
E.心尖部舒张期隆隆样杂音
I think you've got to the point ______ a change is needed, otherwise you'll fail.
A. when B. that C. where D. which