這是很好的問題。你仔細聽 "ㄥ" 和 "ㄨㄥ" 的音，其實是不一樣的。 " ㄨㄥ " 有 " ㄨ " 的音，但 " ㄥ " 沒有。
等你清楚之後，再唸 " ㄈㄥ " 和 " ㄈㄨㄥ " 一次，你就會發現風只能讀成 " ㄈㄥ "。

It's a good question. You listen to " ㄥ " and " ㄨㄥ " carefully. In fact, they are different. " ㄨㄥ " has a sound " ㄨ ", but " ㄥ " hasn't. After understanding, you read " ㄈㄥ " and "ㄈㄨㄥ" again. You will realize
風 is only read " ㄈㄥ ".

=)