例子:
The warmest clothes are made of real sheep's wool, not artificial fabrics like acrylic or rayon. 
照片许可:
CC版权：出处标示，商业用途
Regionalism:
Neutral
Regional variant:
Neutral
Full Expression:
The “ull” Sound (/ʊ/): wool
the hair of sheep and similar animals, which is often then processed to make clothes