—____________?

—Very well, thanks.

A．How are you

B．How do you do

C．Where are you

D．What are you doing

导致慢性肺心病最常见的病因是（）

A.肺脓肿

B.慢性阻塞性肺病

C.反复发生的肺小动脉栓塞

D.先天性肺囊肿

E.支气管扩张