发鼻音/m/的要点在于闭紧双唇，让气流从鼻腔泄出。

A.His wife was cooking（降调）when we walked into the kitchen.（降调）
B.His wife was cooking（降调）when we walked into the kitchen.（升调）
C.His wife was cooking（升调）when we walked into the kitchen.（升调）
D.His wife was cooking（升调）when we walked into the kitchen.（降调）

A.ts
B.tes
C.t’s
D.t

A./dʒ/
B./tr/
C./dr/
D./dz/