Final answer:
The analogy compares the peak or summit of a mountain to the roof of a house, indicating that both are the highest or uppermost parts of their respective structures.
Step-by-step explanation:
The question "...........is to a mountain as roof is to house?" is asking for a comparison between two elements, in which one part of the natural environment corresponds to a part of a man-made structure. The answer creates an analogy between the parts of nature and architecture, highlighting their similarities in terms of function or symbolic importance. In this context, the peak or summit is to a mountain as the roof is to a house, as both are the topmost parts of their respective structures. Just like a roof protects the house and its inhabitants from the elements, the peak or summit represents the highest point of a mountain, often the goal of those who endeavor to climb it.