引起弥散量降低的有()。
A.肺出血
B.肺结核
C.气胸
D.肺间质纤维化
E.红细胞增多症
参考答案:B, C, D
.-----It’s reported that over 1 billion people watched the live opening ceremony of______2010 South Africa World Cup on TV.
-----Yes, news came as______ shock to me.
A.the; the
B./; a
C.the; a
D.a; the
电路断路时负载电阻为()
A.趋向零
B.无限大
C.常数