头颅凹陷性骨折，应首选哪种投照体位()
A．切线位
B．头颅侧位
C．汤氏位
D．颅底位
E．头颅后前位
参考答案：A
John waited until he got back his breath and could speak . [ ]
A. normally
B. commonly
C. regularly
D. formally
用于血小板功能亢进引起的血栓栓塞性疾病防治的是
A．阿司匹林B．肝素C．链激酶D．香豆素类E．氨甲环酸
