Mud is an uncountable noun, it doesn't have a plural form, we don't say muds.
Transport is both countable and uncountable as a noun.
countable
Uncountable
uncountable
The gerund painting is a countable noun, as in "There are 12 paintings in this room."
Transport is both countable and uncountable as a noun.
countable
Uncountable
uncountable
Uncountable
uncountable
uncountable
The gerund painting is a countable noun, as in "There are 12 paintings in this room."
Countable
countable
few is countable
The noun 'steel' is an uncountable (mass) noun, a word for a substance.