The answer should be:
is
<em>The bell for the front door </em> is <em>out of order.</em>
The correct answer to this question is option A) 7.80 years.
Trueeeeeeeeeeeeeeeeeeeeeeeee
A model is a three-dimensional of a person/thing or of a proposed structure.
A mock up is a model or replica of a machine or structure, used for instructional or experimental purposes.
A prototype is a first or preliminary version of a device or vehicle from which other forms are developed.
