对二尖瓣狭窄程度的判定最有价值的是
A．听诊
B．胸部X线摄片
C．心电图检查
D．胸部CT扫描
E．二维超声心动图检查
参考答案：E
低温时下列哪项参数降低（）。
A.血液黏滞度
B.血浆容量
C.血细胞比容
D.中心静脉压
E.微循环阻力
The new tax law only affects people on incomes of over $3,000 per month - _____, the relatively rich
people in society. [ ]
A. on the contrary
B. on the other hand
C. in other words
D. for one thing
x law only affects people on incomes of over $3,000 per month - _____, the relatively rich