输血后肝炎主要为（）
A.甲型病毒性肝炎
B.乙型和丙型病毒性肝炎
C.丁性病毒性肝炎
D.戊型病毒性肝炎
E.庚型病毒性肝炎
参考答案：B
— I heard the phone ringing in the office next door.
— You ________ it. They haven't got a phone yet. [ ]
A. couldn't have head
B. couldn't hear
C. wouldn't have heard
D. didn't hear
幽门痉挛
A．肠套叠病程36小时，全身情况可B．肠管坏死，极度危急时C．口服碳片8小时后由肛门排出D．果酱样血便E．肠套叠病程56小时
