肝素的临床用途有（）
A.脑栓塞
B.心肌梗死
C.DIC晚期
D.体外抗凝
E.蛇咬伤所致弥散性血管内凝血
参考答案：A, B, D
At first, I didn’t know what ____ Facebook was, and now I do know what it is. I have to say, it sounds like ____ huge waste of time.
A．/; the
B．/; a
C．the; a
D．a; the
生物安全实验室中的基础实验室包括一级和二级生物安全实验室。
