（）是由于项目存在众多参与方，因各方的动机和目的不一致导致项目合作的风险，影响项目的进展和项目目标的实现。

A．组织风险

B．技术风险

C．市场风险

D．管理风险

A cofferdam is（）.

A.any deck below the main deck and above the lowest deck

B.a member that gives fore-and-strength

C.made by placing two bulkhead a few feet apart

D.a heavy fore-and-aft beam under the deck