—Have you heard from Nelly recently?

— Yes, I _________ his letters and cards many times while I was in Italy.

A．have received

B．received

C．had received

D．would receive

在建设工程项目风险管理过程中，风险识别最主要的工作成果是（）。

A.风险事件发生的概率

B.风险清单

C.风险事故对项目目标的影响程度

D.风险等级