慢性支气管炎发展成阻塞性肺气肿的过程中最先发生的病理改变是
A.肺泡膨胀
B.肺小动脉痉挛
C.肺纤维化
D.肺泡壁弹性减退
E.细支气管不完全阻塞
参考答案:D
Japan says its Prime Minister promised to provide the world with "maximum transparency"
about ____ accident at the Fukushima nuclear power plant during _____ telephone call. [ ]
A. the; a
B. the; the
C. an; the
D. an; a
航迹向与真航向的差值称为()。
A.风压差
B.流压差
C.风流合压差
D.磁差