come into use是一个固定词组----- 投入使用、实施
This new invention will come into use. 这项新发明即将投入使用!
If this method comes into use, it will faction well.
如果这个方法被实施的话,作用将会是巨大的!
His thought is always good, but it never comes into use,
他的想法总是很好,但是从来没有实施过!
Onlythe new method come into use wll we see its faction. (倒装句)
只有这个方法投入使用,我们才能看到他的作用