We're still at the airport. If it weren't for the delayed flight, we _____ the concert right now. [ ]

A. can be enjoying

B. must have enjoyed

C. would be enjoying

D. should have enjoyed

过敏性紫癜的特征为（）

A.发热、乏力

B.蛋白尿、血尿

C.可累及其他系统如关节、肾脏、肺等

D.非血小板减少性紫癜

E.发病前常有上呼吸道感染、低热、全身不适等前驱症状