慢性肺心病最常见的病因是（）。
A.慢性支气管炎
B.支气管扩张
C.支气管哮喘
D.重症肺结核
E.原发性肺动脉高压
参考答案：A
He likes to play ____ football, but I like to play _____ piano.
A．the; the
B．/; /
C．the; /
D．/; the
气孔指数
