Verbal | Re: Need Explanation on Complex Parallelism Rule for Prepositions

The correct list of parallel elements is:
During the eighteenth century, widespread changes in agriculture, known as the agrarian revolution involved
the
- large-scale introduction
-- of enclosed fields
and
-- of new
---- farming techniques
and
---- crops
and
- the substitution of commercial for subsistence farming.

This is an example of double convolution.

The skeleton is as follows:
the large-scale introduction of A, and ofnew B and C, and the substitution
...

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