How does "evening thoughts" add a new dimension to the story "Sarah's decision"?

there is a sequence and logical steps to give an answer of a trouble.

1) strategy is necessary to develop an project idea.

2) to study and know the environment where you are going to work ( ecosystem).

3)   the materials resources to built the ideas.

4) to give a priority order in the context that you study. in this case human needs.

a. energy is conserved on earth, but matter is not.

i don't see it in your profile.