在双层经营体制中，两个经营层次的关系是通过（）来实现的。
A.承包合同
B.统一计划
C.责、权、利平衡
D.平等互利原则
参考答案：A
_____ she was sick, I was expected to take her place greatly surprised me, for I didn't have much
work experience. [ ]
A. That if
B. That
C. If that
中梁下盖板截换时其接口形式有何规定？
