Answer:
The answer is explained below.
Explanation:
The words used to link pronouns, nouns and phrases to other words within a sentence is called preposition. Long, above, except, near, since and before are prepositions. <em>A noun phrase, noun or pronoun that follows a preposition to complete its meanings is called object of a preposition</em>, it is in objective case.
In 'Wearing high top boots, terry waded through the river' the river is the object of the preposition.