/u:/  soon, moon, food, afternoon, school, too, tooth, spoon, noodles, cartoon, choose, broom, dining-room, balloon等
/u/  look, good, book, cook, foot, football, bookcase, bookmark, goodbye, cooker, woof等
另外，classroom, bathroom, bedroom发两种音。

整理的很全面   辛苦了   谢谢

很细心，学习了。。。

谢谢你，辛苦了。

整理的很全面   辛苦了   谢谢

整理的很全面   辛苦了   谢谢