下列哪一种波长的光线在皮肤上主要产生热效应（）
A.短波紫外线
B.中波紫外线
C.长波紫外线
D.可见光
E.红外线
参考答案：E
--- Roy and Samantha got married last week. Did you go to their wedding?
--- No, I ________ an important meeting in another city.
A．attended
B．have attended
C．had attended
D．was attending
肝外阻塞性黄疸原因不明时，应行下列何种术式（）
A.胆总管十二指肠吻合术
B.胆囊造瘘术
C.胆道探查及引流术
D.胆囊切除
E.肝叶切除术
