How to understand this sentence
polymers are all substances which are made up of at least two monomer units.

May I read it as "all the polymers are made up of at least two monomer units",
if not, what is the difference between these two sentences

Question

How to understand this sentence
polymers are all substances which are made up of at least two monomer units.

May I read it as "all the polymers are made up of at least two monomer units", 
if not, what is the difference between these two sentences

Answer

the first sentence express that every polymers have at least to part which can be different from one polymer to other. just  say thatpolymers consist of at least two part
but the second sentence tell us that there are 2 special kind of unites which is repeating in  every polymers.In other words, all of the polymers have a same kind of unites