I think its A. They establish this section's grim mood. Hope thus helps :D
The supporting details should be included in the Body Paragraphs of an essay. The introduction is an introduction of what you plan to write about, and the thesis is included in the introduction where you specifically mention your main topics/points. However you elaborate on these in the body paragraphs and these elaborations are your supporting details. The conclusion is a summary of your essay and should not be introducing any new information.
The correct answer for the question that is being presented above is this one: "Zero or 0." <span>When you decrease the row height to zero, the row is hidden. In excel, if the row height is set to zero, then the row will be immediately hidden because there is no length that is given.</span>
I think the helping verb is ''how many''
