Directions: In the sentence given below, four words marked as (1), (2), (3), and (4) may not be in their correct positions. Choose the option that specifies the correct pair of words that need to be interchanged to make the sentence grammatically and contextually meaningful.

With portions of the floodgates (1) being inspected after installation of the reservoir (2) and heavy equipment and sediment cleared (3) along the channels, technicians (4) are monitoring the water flow.

The correct answer is Only 1 - 2.

Step-by-Step Explanation:

Let us analyze the original sentence to check the contextual correctness of the highlighted words:
"With portions of the floodgates (1) being inspected after installation of the reservoir (2) and heavy equipment and sediment cleared (3) along the channels, technicians (4) are monitoring the water flow."

Logical & Contextual Analysis:
1. floodgates (1) and reservoir (2): A reservoir is a body of water, while floodgates are engineered structures designed to control water flow. It is contextually appropriate to talk about the "installation of the floodgates" rather than the "installation of the reservoir." Similarly, inspecting "portions of the reservoir" fits the context of checking water areas.
2. Therefore, interchanging (1) floodgates and (2) reservoir fixes the logical sequence of the sentence.
3. cleared (3) and technicians (4): Both words are correctly placed. Sediment and equipment are "cleared" from channels, and "technicians" properly serves as the subject monitoring water flow.

Correct Sentence after Interchange:
"With portions of the reservoir being inspected after installation of the floodgates and heavy equipment and sediment cleared along the channels, technicians are monitoring the water flow."

Thus, the correct pair of words to interchange is 1 - 2.