Question

____ must be placed on timbers or cribbed so as to spread the weight of the crane and the load over a large enough area. outriggers loads slings booms

Explanation:

Outriggers are components of cranes that need to be placed on timbers or cribbed to distribute the weight of the crane and its load over a sufficient area. This is a common practice in construction and engineering (within the Natural Science discipline, specifically Engineering sub - field) to ensure stability and prevent sinking or tipping. Loads refer to the weight being lifted, slings are for holding the load, and booms are the lifting arms, but the description in the sentence best fits outriggers.

Answer:

Outriggers