再生障碍性贫血可能的发病机制是()
A.免疫异常
B.造血微循环异常
C.原发性造血干细胞缺乏
D.继发性造血干细胞缺陷
E.原发性造血干细胞缺陷
参考答案:A, B, D, E
Would you please tell me ________? [ ]
A. when did he come home
B. where he would play football
C. if he had seen the film
D. why he didn’t watch the game
对没有染疫的船舶、航空器,如果来自霍乱疫区,检验检疫机构认为必要时,可以对离船、离航空器的员工、旅客,从离开疫区时算起,实施不超过五日的隔离观察。( )