The sound /oo/ (I dearly wish I could use a phonetic or
phonemic alphabet) can be spelled, in English, in an almost incredible number
of ways:
Blue, blew, shoe, lose, cool, fuse, through. Oo is common:
loose, booze, choose, moose, goose, noose. Also uCe (where C stands for
consonant): accuse, abuse, infuse, allude, intrude, etc.
There is actually some regularity in English
spelling--despite all you hear to contrary, here and elsewhere. That was the thread,
the principle, in the Spelling textbooks on which I worked in one of my first
jobs.
What chaos there is can partly be blamed on Norman scribes
who, after the Norman conquest, put some effort into fixing or straightening
out English spelling--and only made things worse with their band-aid approach
and their frequent failure to properly understand that which they were
tampering with.