( )辅助继电器、计时器、计数器、输入和输出继电器的触点可使用无限次。
参考答案：对
Which of the following statements is correct
A．The definition phase results in the Software Requirements Specificatio
B．Testing is optional in software life cycl
C．CASE tools can only aid in the design phase of a software life cycl
D．A change during a later phase does not require the documentation of all earlier phases to be update
什么是转基因食品？转基因食品对人类的意义？
