Mr Clark thanked God for saving their lives and turning _____he felt was a tragedy into a blessing.

A．which

B．what

C．how

D．that

市政公用工程项目的施工组织设计必须经（）批准后方可实施。

A.项目经理

B.企业技术负责人

C.项目总工

D.总监理工程师