■ hair

通常是不可数名词，只用单数。

• His hair is black.他的头发是黑色的。

但是也可以作为可数名词指一根根的头发。

• So why has he got two blonde hairs on his jacket?那么为什么他外套上有两根金色头发呢？

• 's
• safe
• safety
• sailor
• salary
• salary
• salary, wage 与 pay
• sale
• same
• sanguinary
• sanguinary 与 sanguine
• sanguine
• save
• saving
• say
• says you
• scant
• scarcely
• scatter
• school
• science
• sea
• search
• seasonable
• seasonable 与 seasonal