Thousands of people lined up to lay flowers in front of a 28-story high-rise in Shanghai, _______a terrible fire killed at least 58 people.

A．when

B．where

C．which

D．what

下列风险识别方法中，有可能发现其他识别方法难以识别出的工程风险的方法是 ( )。

A．流程图法

B．初始清单法

C．经验数据法

D．风险调查法