一种发生于下肢的结节性红斑性、皮肤血管炎性皮肤病，中医称之为（）
A.猫眼疮
B.瓜藤缠
C.黧黑斑
D.红蝴蝶疮
E.油风
参考答案：B
设集合A={x|x2+4x=0}，B={x|x2+2(a+1)x+a2-1=0}，A∩B=B，求实数a的值．
I wish to thank Professor Smith，without ________ help I would never have got this far.(2012·天津)
A．who
B．whose
C．whom
D．which
