"You'll have to wait for an hour, ________is, about 10:20, ________the examination result will

come out," the teacher said to me.[ ]

A. that; when        

B. which; that      

C. that; before        

D. which; when

可以把多目标并为单个目标，使用单目标的决策问题的方法求解多目标问题。