# 2.2.2 p/b
p/b 的发声动作一样，都是先把嘴唇闭合，而后用气流冲开嘴唇。p 没有声带振动，而 b 有声带振动。
The pronunciation of p and b share the same mechanism, where the lips first close, then air pressure forces them apart. The difference lies in the vibration of the vocal cords: p doesn't involve vocal cord vibration, while b does.
这两个辅音都会自然带有很轻微的 ʊ 的音色 —— 是气流冲开嘴唇自然产生的声音。
Both consonants naturally have a slight ʊ sound, which is a byproduct of the air bursting past lips.
中国学生在起初的时候常常分不清 *please* 和 *police* —— 可事实上，这两个词的区别很明显：
Chinese students often struggle to distinguish between *please* and *police* at first when learning English. But they are distinctly different:
* *please* 只有一个音节：pliːz，而 *police* 有两个音节： pəˈliːs；
* *please* consists of a single syllable: pliːz, while *police* has two syllables: pəˈliːs.
* 前者末尾的辅音是 z，后者末尾的辅音是 s；
* The final consonant in *please* is a z sound, whereas in *police*, it's an s sound.
* 最关键的，前者开头最多听起来是 pʊ，而后者不一样，是 p 和另外一个元音构成的音节： pə……
* Most importantly, the initial sound in *please* might be heard as pʊ, but in *police*, it's different. It's a syllable composed of p and another vowel: pə...