问cool和book中o的发音一样吗

cool[ku:l]和book[bʊk]中o的发音不一样:[u:]，[ʊ]

He breathed deeply of the cool air .他深深地吸了一口清凉的空气。

I 'm going into the wood to cool off .我想进树林子里去凉快凉快。

It's cooling off my mosquito bites .它消掉了我身上蚊子咬的肿块。

A rapid shower had cooled the air .一场骤然而降的阵雨凉爽宜人。

She cooled her child 's fevered brow .她给孩子滚烫的额头降温。