优海

当前面的元音是非重读元音时，f，θ和x进一步变化成b，d和g。
Verner's Law says that voiceless fricatives, when immediately following an unstressed syllable in the same word, underwent voicing.
centum -> hundred
PIE upo -> over
PIE apo -> off
 
中元音2个: / ә / / ә: / 
后元音6个: / u / / u: / / ɔ / / ɔ: / / Λ / / a: /
前元音4个: / i: / / i / / e / / æ /
 
i-umlaut(i-mutation), a-mutation, u-mutation
 
唇	b p m f
齿	d t n l
硬腭	dʒ s tʃ
软腭	g k h
 
Green's Low
b -> p -> f
d -> t -> th
g -> k -> h
 
a - e - i - o - u
t - d - s 前齿音
b - p - m - f - v - d 前唇音
u - v - w
g - k/c - h 喉音
l - m - n - r 鼻音 侧音
s - c - z
 
r - s - t
 
b - d
m - w
y - g
y - j
g - w
 
ad-vjpm
a*-bcfglnqrst
a-sp,sc,st
 
sub-btnm
su*-cfgpc
 
ab: abs,aps,as,au,a
con: cog,col,com,cor,co
in: im,il,ir,ig
en: em
syn: sym,sy
ob: oc,of,op,o
trans: tran,tra
dis: dif,dir,di
ex: ef,e,ec,es
 
drag=trac(t)
break=frac(t)
make=fact
miss=mit
pend=pens
grad=gress 走
hundred=centi
hand=chir
hard=crac
carve=gram,graph

malleolus: 踝
tibia: 胫骨
tuberosity: 粗隆
fibula: 腓骨
phlegm: 粘液
bile: 胆汁
chole: 胆汁
etymology: 词源
 
adenosine: 腺苷
adenine: 维生素B4、腺嘌呤
purine: 嘌呤
guanine: 鸟嘌呤
pyrimidine: 嘧啶
cytosine: 胞嘧啶
thymine: 胸腺嘧啶
uracil: 尿嘧啶
glycoside: 糖苷
ribose: 核糖
glucose: 葡萄糖
choline: 胆碱
Cholesterol: 胆固醇
fructose: 果糖
peptide: 肽
acyl: 酰
ester: 酯
lipid: 脂
aldose: 醛糖
steroid: 类固醇
histone: 组蛋白
 
halide: 卤
fluoride: 氟
chloride: 氯
bromide: 溴
iodide: 碘
alkane: 烷
alkene: 烯
alkyne: 炔
alcohol: 醇
aldehyde: 醛
acetal: 缩醛
ketone: 酮
ketal: 缩酮
amine: 胺
imine: 亚胺
aminal: 缩醛胺
ether: 醚
oxime: 肟，亚硝基化合物
aldoxime: 硝酮
hydrazone: 腙
azine: 嗪
pyridine: 吡啶
cyanohydrin: 羟腈
nitrile: 腈
hydrazide: 酰肼
amidine: 脒
urea: 脲
enol: 烯醇
mercaptan: 硫醇
sulfone: 砜
alkyl halide: 卤代烷
epoxide: 环氧化物
lactone: 内酯
aryl group: 芳基
phenyl group: 苯基
Phenol: 苯酚
naphthalene: 萘
benzyl group: 苄基
ketyl radical: 羰自由基
dextro isomer: 右旋异构体
laevo isomer: 左旋异构体
chiral: 手性