Giving up my job to go back to full­time education was a big ________，but now I know it was the best decision I ever made.                                      (2011·湖北，22)

A．project

B．commitment

C．competition

D．ambition

变应性皮肤一系统性血管炎可见于（）

A.白塞综合征

B.变应性皮肤血管炎

C.皮肤结节性血管炎

D.变应性肉芽肿

E.血清病