()轧机可实现负偏差轧制。
参考答案:短应力线
一列横波在x轴上传播,在t1=0时刻波形如下图实线所示,t2=0.05s时刻波形如下图虚线所示。
(1)由波形曲线读出这列波的振幅和波长;
(2)若周期大于,则最大波速是多少?方向如何?
You promised to________the goods to our place immediately, but we haven't seen any of them yet. [ ]
A. pass
B. relay
C. deliver
D. provide