心跳突然停止,多久后可能会发生脑损伤()
A.2~4min
B.4~6min
C.6~8min
D.8~10min
E.10~15min
参考答案:B
Do you know the man from _____ house the pictures were stolen?[ ]
A.which
B.that
C.what
D.whose
不受尼奎斯特极限限制的超声技术是()
A.脉冲型多普勒技术
B.连续型多普勒技术
C.高频重复脉冲频率技术
D.彩色多普勒技术
E.M型超声技术