滞后效应
参考答案：
由于松弛过程的存在，材料的形变必然落后于应力的变化，聚合物对外力响应的滞后现象叫滞后效应。
在软件设计中不使用的工具是
A．系统结构图
B．程序流程图
C．PAD图
D．数据流图(DFD图)
An analyst stated that the mean of the standard normal distribution always has a value of zero but that the standard deviation of the standard normal distribution can take on a value from 0 to 1. 0. Is the analyst correct with respect to the value of the standard normal distribution’s:mean Standard deviation ①A. No No ②B. No Yes ③C. Yes No A．① B．② C．③
