( )着重反映的是某模块间的隶属关系，即模块间的调用关系和层次关系。
A．程序流程图
B．数据流图
C．E—R图
D．结构图
参考答案：D
The wings of the plane, which stretched out for 80 feet, were ______ of its body.
A．more than the length twice
B．more than twice the length
C．twice the length more than
D．twice more than the length
一氧化碳和氢在催化剂作用下可以合成什么（）？
A、甲醇
B、乙醇
C、汽油
D、烯烃
