My father likes playing golf；he's really enthusiastic________it.

A．by

B．with

C．about

D．on

关于Crohn病，下列哪项是正确的（）.

A.病变多见于末段回肠和邻近结肠

B.常有粘液脓血便

C.并发症以肠梗阻最常见

D.病变呈连续性分布

E.病变肠段之间粘膜外观正常