Answer:
stability; resistance; rigidity.
Explanation:
Okay, let us fill in the gap in the question above. Please note that the capitalized words are the missing words to fill in the gap.
"Unless a structural element is intended to be battered, sloped, or cambered (or some other non-conforming position), wood, steel, and concrete should always be installed and maintained STABILITY , RESISTANCE , and RIGIDITY. These conditions are critical in order to ensure maximum stability, structural performance and user satisfaction."
This question has to deal with buildings or say structural (civil) engineering. The definition to the missing words are given below:
STABILITY: Stability occurs when we have the center of gravity coinciding with the base of the structure.
RESISTANCE : Resistance simply means the 'tension' that is is how much the structure can resist an applied force.
RIGIDITY : RIGIDITY can also be associated with resistance and it is the property of a structure to resist bending.