强调计划执行过程具有应变能力的是（）
A.限定因素原理
B.许诺原理
C.灵活性原理
D.改变航道原理
参考答案：D
250. Jack is a very stubborn(顽固的) person. I was unable to _____ him to do as I said. I want to ask you to have a word with him.
A．let
B．make
C．prevent
D．Persuade
同步调相机的同步是什么意思？
