发音
双唇外突成圆形
过渡双唇扁平分开

单词
boy toy soy
boil soil spoil
joy royal annoy
join joint point
coin oil oyster
voice noise poison
destroy employ enjoy
appoint avoid choice

句子
Don’t boil the oyster.
They enjoy the meal.
The toys are for boys.
The coin has two sides.
The voice is very deep.

同音
boy buoy