前位限定词：
all both half.
double twice three times.one third two fifths.
what such a/an
中位限定词：
a/an the zero
this that these those
my your Merry's my friend's.
some any no every each either neither enough
what(ever) which(ever) .whose
后位限定词：
one two three.
first second third .
next last other another.
many much (a) few (a) little fewer less.
several plenty of a lot of a large/small amount of.
