A.2π
B.π
C.
D.
[单选题]A.2πB.πC.D.
[单选题]A.B.C.D.
[单选题]A.肺结核B.中央型肺癌C.支气管肺炎D.肺脓肿
[单选题]A.15AB.0C.D.3A
[单选题]A.1B.2C.3D.4