Topic sentence development task

Task: Study the following possible ways of developing the topic sentence, and identify the functions being performed.

Topic sentence:
All languages have the same purpose - to communicate thoughts - and yet they achieve this single aim in a multiplicity of ways.

1. It appears there is no feature of grammar or syntax that is indispensable or universal.
   Contrasting
   Exemplifying
   Elaborating
   Defining
   Qualifying
   
2. Animal communication, on the other hand, is constrained in many ways.
   Contrasting
   Exemplifying
   Elaborating
   Defining
   Qualifying
   
3. Time is expressed in different languages in many different ways.
   Contrasting
   Exemplifying
   Elaborating
   Defining
   Qualifying
   
4. Despite this, there are also universal features across languages.
   Contrasting
   Exemplifying
   Elaborating
   Defining
   Qualifying
   
5. By communication, of course, we mean the ability to press grammatical, lexical and phonological resources into service in contexts of use.
   Contrasting
   Exemplifying
   Elaborating
   Defining
   Qualifying