The old man asked me to write a letter for him.那位老人要我替他写封信.There's no time for me to write a letter to him.我来不及写信给他了.We could write a letter to the headmaster.我们不妨给校长写封信....
你能用拉削技术制作齿轮 吗 ?A : Can you use broaching to make a gear?注意: 在进入拉削时一定要关闭放气开关.Notice: When broaching, make sure that the air escape cock is closed.其中计算所得到的拉削力, 必须小于拉床的实际拉力.Which has been calculated Broaching, and must be l...