Seldinger穿刺法经皮向血管快速穿刺采用的角度为()
A.10°~20°
B.60°~80°
C.30°~60°
D.10°~15°
E.30°~40°
参考答案:E
She looks much older than her age ____ ten-year hard work. [ ]
A. because
B. because of
C. as a result
D. so that
能激活胰蛋白酶原的物质是()
A.肠激酶
B.钾离子
C.钠离子
D.盐酸
E.磷脂酶