v.分离，筛选,
Merriam-Webster Online Dictionary
sift (verb)transitive verb
1.
a) to put through a sieve - sift flour
b) to separate or separate out by or as if by putting through a sieve
2.
to go through especially to sort out what is useful or valuable - sifted the evidence often used with through sift through a pile of old letters
3.
intransitive verb
to scatter by or as if by - sifting sift sugar on a cake
1.
to use a sieve
2.
to pass or fall as if through a sieve