They could have attended the awarding ceremony，but their flight      due to the bad weather．

A．was delayed

B．had been delayed

C．has delayed

D．was delaying

控制法是指避免、消除风险或减少风险发生频率及控制风险损失扩大的一种风险管理方法，主要包括( )。

A．避免

B．识别

C．抑制

D．风险中和

E．集合或分散