Final answer:
In her writing, Mairs refers to the most important struts in the framework of her existence as the 'impalpable sustenance' she derives from the simple, compact, well-joined scheme of her life.
Step-by-step explanation:
In her writing, Mairs refers to the most important struts in the framework of her existence as the 'impalpable sustenance' she derives from the simple, compact, well-joined scheme of her life. She emphasizes that she, like everyone else, is disintegrated yet still part of the scheme, and that the ties between her and others are of utmost importance.