A developer tries to use `z-index` on a plain block-level “ outside of any grid, and it has no effect until `position: relative` is added; inside a grid container, does a grid item need that same `position: relative` for `z-index` to work?

18. Located immediately superior, anterior, and medial to each kidney is ——-.

A grid container defines three fixed 200px columns inside a much wider container, then sets `justify-content` and `align-content`; why do these two properties have any visible effect here, when `justify-items`/`align-items` alone would not in this situation?

A patient is prepped for a C-section. The Surgeon asked for a knife to make the incision. What kind of incision will the doctor be making? 

During an open Appendectomy what small retractors can be used to use with visualization into the abdomen?

Where is the V2 electrode typically placed?

The V1 electrode is typically placed in which intercostal space?

A `grid-template-areas` map includes the row `”. footer”;` inside a two-column grid; what does the `.` represent in that row?

Two items are placed in the same grid cell, and neither has a `z-index` set; which one appears on top by default?

A page uses Grid to lay out its overall header/sidebar/main/footer structure, and then uses Flexbox inside the header to line up a logo and a row of nav links; what does this combination illustrate?