(1) Shipping along rivers is not as popular as it once was. (2) It is done by air and trucking on interstates. (3) Rivers still provide viable routes for shipping, but it is no longer the most feasible method for moving materials. (4) As rivers declined in popularity, other shipping methods took their place as the best ways to ship merchandise. Which sentence lacks a logical transition?

3. Rivers still provide viable routes for shipping, but it is no longer the most feasible method for moving materials.

Explanation:

For a sentence to have a logical transition, there must be an accurate subject-verb or subject-pronoun agreement. It as a pronoun can be used as a subject or object in a sentence. When It is used to describe a subject, the subject is usually in the singular form. For example,

1. It is a book.

The sentence, 'Books are a good source of earning, but it is going extinct' is not correct because there is no agreement between the subject which is in the plural form and the pronoun.

So the third sentence should be worded as 'Rivers still provide viable routes for shipping, but they are no longer the most feasible method for moving materials'.