How can the page numbers of papers not be displayed on the first and second pages, I and ii on the third and fourth pages, and normal 1, 2, 3 on the fifth page? In addition, the titles are crossed.

Insert section break at the end of the second page, and insert → separator → section break (continuous).

Select the footer on page 3, and then click Link to Previous Page in the header footer toolbar to cancel it.

Set the page number format → Select I, ii, … (the third and fourth pages) → Set the starting page number as 1→ OK → Insert the page number.

At this point, if the first two pages still have page numbers, just select Delete.

Repeat the above steps on page 5.