Final answer:
The correct word to complete the sentence is 'haul,' as it accurately describes the process of trucks transporting heavy materials like concrete and steel, which is common in construction and engineering projects.
Step-by-step explanation:
Trucks started to haul concrete and steel from the original east span of the San Francisco Oakland Bay Bridge and transport it to another site.
The word 'haul' is appropriate as it conveys the action of transporting heavy materials. In the context of construction and engineering, materials such as concrete and steel are often moved by trucks from one location to another as part of the demolition or construction process.
Examples of large-scale engineering projects where hauling is an integral part include the construction of notable bridges like the Golden Gate Bridge and the Brooklyn Bridge which involved extensive logistics in the transportation of materials.