只能修饰可数名词的：
a large/ great/ good number of,
a good/ great many,
dozens of,
scores of,
quite a few
只能修饰不可数名词的：
a great deal of,
a large amount of,
quite a little,
a large sum of
既可修饰可数也可修饰不可数名词的：
plenty of,
a lot of,
lots of,
a large quantity of,
a good supply of