怎样用英文表达“一根头发”及“在整个过程中”
a thread of hair
in the whole process
头发不可数，只有在说一根白发时才说:a grey hair.
during the course
a hair
强调时为a single hair
during the course(of)
one single hair
during the entire process of ...
用a piece of hair 不就行了?
during the whole precess