找出画线部分读音与其他单词不同的选项，将序号填入括号内。

①____ A. good         B. cook         C. moon

②____ A. forty         B. doctor        C.morning

③____ A. brown        B.how          C. window

④____ A. duty          B. bus           C. must

⑤____ A. horse          B. house         C. mouse