找带有oo字母的单词，要40个，音标是[u：]

一般来说双oo在字母m, n, l, th, se前发长u: 例如tooth, spoon, moon,soon ,too ,broom,school,room ,noon ,afternoon ,
food ,cool,choose ,bloom ,boot,troop,loose,midnoon,oof，oofy，crool，croon，crooner，cuckoo，noodle，noodlehead，noodlework，noonday，noonflower，nooning，noontide，noontime，noopsyche，noose，nootkatone，coon，oolong，oom，oose，ooze，pooch，pood，poodle，poof，pooh，pooja，pool，poolside，poop……

在k前一般是短音例如book cook brook
在带有room的组合词中发短音,如classroom,sitting-room,artroom……

bloom,boot,cool,foot,moon,root,school,soon,too,troop,room,zoo
tooth, spoon, moon, broom, school

补充：look,book,