Tick any marks below and the reader keeps them loaded but invisible — the page is already spaced and laid out for them, so nothing jumps. Hold the Shift key and they all appear; let go and they vanish again. Read a clean page, flash the helps the instant you want them. A ticked mark belongs to Quick Features even if it's switched on in its own menu — it goes hidden and waits for Shift. Its row in the other menus shows a small ⚡ tag while Quick Features holds it.
Hover any word while reading and a slim bar at the bottom of the screen shows the original word, its dictionary form, meaning, and grammar — a quick reference without opening the Word panel.