影响冷列的因素和影响（）的因素是一致的。
A.铸件变形
B.热裂
C.铸造应力
D.温裂
参考答案：C
John _______ for London this afternoon and his flight _______ off at 18:20.
A．is about to leave; will take
B．is leaving; takes
C．is going to leave; is taking
D．is to leave; is about to take
流量脉动与水动力不稳定的区别有什么？
