There are lots of problems in your hometown, but we're happy to see many of them________.                                   

A．are solving

B．are solved

C．have solved

D．are being solved

关于肺内支气管与肺动脉的下列描述中哪一项是错误的（）

A.肺内支气管一般与肺动脉分支并行

B.二者的管径大致相等

C.肺外围一般不能显示支气管的断面

D.肺外围一般可显示肺动脉分支的断面

E.伴行的支气管可以比相邻肺动脉粗2倍以上