下列哪项是为了降低项目建设期风险（）。
A、要求借款人签订长期供销合同
B、租赁合同
C、使用金融衍生工具
D、为项目投保商业保险
参考答案：D
A backlash below a lock is defined as a（）.
A.current setting your vessel on the wall
B.current setting into the lock chamber
C.an eddy working along the lower guide wall
D.current setting counterclockwise
