铝合金材料塑性好、熔点低、铣削时粘刀严重,故铣刀的前、后面粗糙度值要小。用硬质合金应取()类刀片,以减小与铝合金的化学亲和力。
A、YG
B、YT
C、YW
参考答案:A
—Where is my backpack?
—It's _____ the table, _____ the floor.[ ]
A. on; under
B. on; on
C. under; on