轧槽是什么?
参考答案:
刻在一个轧辊上用来轧制轧件的凸棱或凹槽,也就是轧前时轧辊与轧件接触的部分。
已知代数式x +2y的值是-3,则代数式-2x-4y +1的值是 [ ]
A.7
B.-7
C.-5
D.5
Speaker A: If I were you, I'd ride a bike to work. Taking a crowded bus during rush hours is really terrible.Speaker B: ______
A.Yeah, riding a bike is a healthful activity. Don't you think
B.Yes, you're right. Buses are always very crowded during the rush hours.
C.Thank you for your advice. But my bike has got a flat tyre.
D.Certainly. I don't see Why so many people go to work by bus rather than by bike.