我将派儿子去取书.I'll send my boy round to collect the book.妈妈派哥哥去取行李.Mother sent my brother for the luggage.他们派他去取报纸.They sent him out to get the newspaper....
建立了砂轮的球基渐开螺旋面方程和分度球面螺旋线方程,给出螺旋运动参数、螺旋线导程.The mechanism of grinding internal gear of spherical worm emery - wheel is researched.正圆锥螺旋面是正圆柱螺旋面被同轴正圆锥面截得.The ortho cone helicoid was used interrsect intercept by the ortho con...