sections

line numbering is a section setting, exactly like margins, columns or page borders — it can never apply to "part of" a document unless that part is its own section first. Without a break between the TOC and the content, line numbers would also appear on the TOC page, because there would only be one section covering both, so the numbering would not start "from the page after" no matter how the Line Numbers dialog is configured. The three actions are: begin in the right place (which usually means creating the section break first), switch numbering on, and set restart each page — each is independently checkable.

a border (1 mark) restricted to the first page (1 mark). The "Apply to" list is how Word limits a border to one page — a page border, like margins or line numbering, is a section-level property, so without choosing "This section – First page only" the identical border would print on every page of that section, which is a different, lower-scoring result even though a border clearly exists.

marks for two columns, line between, first column 7 cm. Equal column width must be off, otherwise Word forces both columns to match, which directly contradicts an instruction asking for one specific, uneven width. "Selected text" makes Word wrap the passage in continuous section breaks so the heading and rest of the page stay single column — columns, like line numbering and margins, are a section property, so only the selected passage can become its own section while everything around it is left alone. The paper tells you to ignore the page border change, which happens because the new sections affect the "first page only" border from 2.1: inserting section breaks changes which pages count as part of that first section, a side effect of the same section mechanism rather than a mistake on your part.