同一台造粒喷头，提高转速时产量提高。
参考答案：对
---I wonder why Mr Green hasn’t showed up at the meeting yet.
---I’m not sure, but he _______ in a traffic jam driving here.
A．could be stuck
B．might stuck
C．might have been stuck
D．must have stuck
原煤取样装臵行走装臵两侧钢轨顶面标高偏差应小于±（）mm。
A.1
B.2
C.3
