将“sifting"翻译成中文

Larger particles may need to be removed by sifting and crushed to reduce their size;

去除较大粒子可能需要用筛分和压碎减小其体积的办法;

And in that situation, sifting through the wreckage of a suicide drone attack, it will be very difficult to say who sent that weapon.

在这种情况,即使仔细筛查 无人机自杀式攻击的残骸, 也很难说谁发射了这个武器。