经典的凝血瀑布学说，内源性凝血途径的启动因子是（）
A.因子Ⅺ
B.因子Ⅻ
C.因子Ⅶ
D.因子Ⅲ
E.因子Ⅴ
参考答案：B
_______ that he made an obvious mistake, Jeff went on with his speech.
A．Not realized
B．Not to realize
C．Not to have realized
D．Not realizing
两坐骨结节内侧缘的距离为坐骨结节间径。
