皮亚杰认为:任何知识都发源于(),主客体的各自联系分别演化成为()和()。
参考答案:动作;关于客体的物理知识;关于主体的逻辑数理知识
I don't remember how many years ago _____ people began to grow crops.
[ ]
A. it was when
B. it was that
C. was it that
D. was it when
经营安全状况分析包括( )。
A.安全余额
B.销售额平衡点
C.经营安全率
D.销售额的差额
E.安全余额大小