多选题 The software structure is an expression of the relationship among software module,in the following phasE．Which are not the relationship among module software modules(    ).
   ①calling relation  ②belonging relation
   ③execution relation ④process relation
   A．①②    B．②③
   C．③④  D．none
【正确答案】 A
【答案解析】在软件设计的层次图中，充分地体现了模块化结构软件中，模块之间的调用和从属关系；模块的执行关系和处理关系在软件结构中体现不出来，所以答案为A。