除脏是为了保证版面的整洁性和空白部位的亲水性，对版面上出现的脏点、影印、底灰和多余的规线、图文等进行去除的一种修正方法。
参考答案：对
Thanks for your order of December 7.Unfortunately the ordered goods are now（）stock and will not be available before the end of the year.
A．in
B．on
C．off
D．out of
滚珠螺纹丝杠CDM50 10LH—3—T3为外循环插管式，双螺母垫片预紧，精度为10级的滚珠丝杠。( )
