Which parts of speech is "IS"?

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.

her eyes water as she let her go

her mothers hand goes limp

face white and pale

lips blue and stale

she is gone

sadness fills her body

she collapses to her knees

as her mothers disease leaves the girl alone