下列哪项与单纯性下肢静脉曲张的发病有关
A.静脉壁薄弱
B.静脉内压力升高
C.工作长久站立
D.深静脉血栓形成
E.静脉瓣膜功能不全
参考答案:A,B,C,E
I was _______ when I heard the _______ news!
A.disappointing; disappointed
B.disappointed; disappointing
C.disappointing; disappointing
D.disappointed; disappointed
()成为拓展服务地域范围的重要形式。